diff --git a/.eslintignore b/.eslintignore
index e9067bb70d..2b550ca81d 100644
--- a/.eslintignore
+++ b/.eslintignore
@@ -1 +1,3 @@
 lib/to-iso-string/
+test/**/*
+!test/runner.js
diff --git a/.gitignore b/.gitignore
index 99fb76a31b..fa1c0b0ccf 100644
--- a/.gitignore
+++ b/.gitignore
@@ -13,3 +13,5 @@ lib/browser/diff.js
 npm-debug.log*
 .envrc
 .karma/
+*.orig
+
diff --git a/Makefile b/Makefile
index d6501ec33b..4161c4627b 100644
--- a/Makefile
+++ b/Makefile
@@ -25,7 +25,7 @@ clean:
 
 lint:
 	@printf "==> [Test :: Lint]\n"
-	$(ESLINT) "lib/**/*.js"
+	$(ESLINT) browser-entry.js index.js karma.conf.js bin/mocha bin/_mocha "lib/**/*.js" "scripts/**/*.js" test
 
 test-node: test-bdd test-tdd test-qunit test-exports test-unit test-integration test-jsapi test-compilers test-glob test-requires test-reporters test-only test-global-only
 
@@ -82,31 +82,31 @@ test-requires:
 		--require test/acceptance/require/b.coffee \
 		--require test/acceptance/require/c.js \
 		--require test/acceptance/require/d.coffee \
-		test/acceptance/require/require.js
+		test/acceptance/require/require.spec.js
 
 test-bdd:
 	@printf "==> [Test :: BDD]\n"
 	$(MOCHA) --reporter $(REPORTER) \
 		--ui bdd \
-		test/acceptance/interfaces/bdd
+		test/acceptance/interfaces/bdd.spec
 
 test-tdd:
 	@printf "==> [Test :: TDD]\n"
 	$(MOCHA) --reporter $(REPORTER) \
 		--ui tdd \
-		test/acceptance/interfaces/tdd
+		test/acceptance/interfaces/tdd.spec
 
 test-qunit:
 	@printf "==> [Test :: QUnit]\n"
 	$(MOCHA) --reporter $(REPORTER) \
 		--ui qunit \
-		test/acceptance/interfaces/qunit
+		test/acceptance/interfaces/qunit.spec
 
 test-exports:
 	@printf "==> [Test :: Exports]\n"
 	$(MOCHA) --reporter $(REPORTER) \
 		--ui exports \
-		test/acceptance/interfaces/exports
+		test/acceptance/interfaces/exports.spec
 
 test-glob:
 	@printf "==> [Test :: Glob]\n"
@@ -121,29 +121,29 @@ test-only:
 	@printf "==> [Test :: Only]\n"
 	$(MOCHA) --reporter $(REPORTER) \
 		--ui tdd \
-		test/acceptance/misc/only/tdd
+		test/acceptance/misc/only/tdd.spec
 
 	$(MOCHA) --reporter $(REPORTER) \
 		--ui bdd \
-		test/acceptance/misc/only/bdd
+		test/acceptance/misc/only/bdd.spec
 
 	$(MOCHA) --reporter $(REPORTER) \
 		--ui qunit \
-		test/acceptance/misc/only/bdd-require
+		test/acceptance/misc/only/bdd-require.spec
 
 test-global-only:
 	@printf "==> [Test :: Global Only]\n"
 	$(MOCHA) --reporter $(REPORTER) \
 		--ui tdd \
-		test/acceptance/misc/only/global/tdd
+		test/acceptance/misc/only/global/tdd.spec
 
 	$(MOCHA) --reporter $(REPORTER) \
 		--ui bdd \
-		test/acceptance/misc/only/global/bdd
+		test/acceptance/misc/only/global/bdd.spec
 
 	$(MOCHA) --reporter $(REPORTER) \
 		--ui qunit \
-		test/acceptance/misc/only/global/qunit
+		test/acceptance/misc/only/global/qunit.spec
 
 test-mocha:
 	@printf "==> [Test :: Mocha]\n"
@@ -153,19 +153,19 @@ test-mocha:
 non-tty:
 	@printf "==> [Test :: Non-TTY]\n"
 	$(MOCHA) --reporter dot \
-		test/acceptance/interfaces/bdd 2>&1 > /tmp/dot.out
+		test/acceptance/interfaces/bdd.spec 2>&1 > /tmp/dot.out
 
 	@echo dot:
 	@cat /tmp/dot.out
 
 	$(MOCHA) --reporter list \
-		test/acceptance/interfaces/bdd 2>&1 > /tmp/list.out
+		test/acceptance/interfaces/bdd.spec 2>&1 > /tmp/list.out
 
 	@echo list:
 	@cat /tmp/list.out
 
 	$(MOCHA) --reporter spec \
-		test/acceptance/interfaces/bdd 2>&1 > /tmp/spec.out
+		test/acceptance/interfaces/bdd.spec 2>&1 > /tmp/spec.out
 
 	@echo spec:
 	@cat /tmp/spec.out
diff --git a/bin/_mocha b/bin/_mocha
index 11d3d0c662..b355e28352 100755
--- a/bin/_mocha
+++ b/bin/_mocha
@@ -1,31 +1,33 @@
 #!/usr/bin/env node
 
+/* eslint no-unused-vars: off */
+
 /**
  * Module dependencies.
  */
 
-var program = require('commander'),
-  path = require('path'),
-  fs = require('fs'),
-  resolve = path.resolve,
-  exists = fs.existsSync || path.existsSync,
-  Mocha = require('../'),
-  utils = Mocha.utils,
-  interfaceNames = Object.keys(Mocha.interfaces),
-  join = path.join,
-  cwd = process.cwd(),
-  getOptions = require('./options'),
-  mocha = new Mocha;
+var program = require('commander');
+var path = require('path');
+var fs = require('fs');
+var resolve = path.resolve;
+var exists = fs.existsSync || path.existsSync;
+var Mocha = require('../');
+var utils = Mocha.utils;
+var interfaceNames = Object.keys(Mocha.interfaces);
+var join = path.join;
+var cwd = process.cwd();
+var getOptions = require('./options');
+var mocha = new Mocha();
 
 /**
  * Save timer references to avoid Sinon interfering (see GH-237).
  */
 
-var Date = global.Date
-  , setTimeout = global.setTimeout
-  , setInterval = global.setInterval
-  , clearTimeout = global.clearTimeout
-  , clearInterval = global.clearInterval;
+var Date = global.Date;
+var setTimeout = global.setTimeout;
+var setInterval = global.setInterval;
+var clearTimeout = global.clearTimeout;
+var clearInterval = global.clearInterval;
 
 /**
  * Files.
@@ -50,23 +52,23 @@ var requires = [];
  */
 
 var images = {
-    fail: __dirname + '/../images/error.png'
-  , pass: __dirname + '/../images/ok.png'
+  fail: path.join(__dirname, '..', 'images', 'error.png'),
+  pass: path.join(__dirname, '..', 'images', 'ok.png')
 };
 
 // options
 
 program
-  .version(JSON.parse(fs.readFileSync(__dirname + '/../package.json', 'utf8')).version)
+  .version(JSON.parse(fs.readFileSync(path.join(__dirname, '..', 'package.json'), 'utf8')).version)
   .usage('[debug] [options] [files]')
-  .option('-A, --async-only', "force all tests to take a callback (async) or return a promise")
+  .option('-A, --async-only', 'force all tests to take a callback (async) or return a promise')
   .option('-c, --colors', 'force enabling of colors')
   .option('-C, --no-colors', 'force disabling of colors')
   .option('-G, --growl', 'enable growl notification support')
   .option('-O, --reporter-options <k=v,k2=v2,...>', 'reporter-specific options')
   .option('-R, --reporter <name>', 'specify the reporter to use', 'spec')
-  .option('-S, --sort', "sort test files")
-  .option('-b, --bail', "bail after first test failure")
+  .option('-S, --sort', 'sort test files')
+  .option('-b, --bail', 'bail after first test failure')
   .option('-d, --debug', "enable node's debugger, synonym for node --debug")
   .option('-g, --grep <pattern>', 'only run tests matching <pattern>')
   .option('-f, --fgrep <string>', 'only run tests containing <string>')
@@ -103,7 +105,7 @@ program
   .option('--trace-deprecation', 'show stack traces on deprecations')
   .option('--use_strict', 'enforce strict mode')
   .option('--watch-extensions <ext>,...', 'additional extensions to monitor with --watch', list, [])
-  .option('--delay', 'wait for async suite definition')
+  .option('--delay', 'wait for async suite definition');
 
 program._name = 'mocha';
 
@@ -112,7 +114,7 @@ program._name = 'mocha';
 program
   .command('init <path>')
   .description('initialize a client-side mocha setup at <path>')
-  .action(function(path){
+  .action(function(path) {
     var mkdir = require('mkdirp');
     mkdir.sync(path);
     var css = fs.readFileSync(join(__dirname, '..', 'mocha.css'));
@@ -127,13 +129,13 @@ program
 
 // --globals
 
-program.on('globals', function(val){
+program.on('globals', function(val) {
   globals = globals.concat(list(val));
 });
 
 // --reporters
 
-program.on('reporters', function(){
+program.on('reporters', function() {
   console.log();
   console.log('    dot - dot matrix');
   console.log('    doc - html documentation');
@@ -154,7 +156,7 @@ program.on('reporters', function(){
 
 // --interfaces
 
-program.on('interfaces', function(){
+program.on('interfaces', function() {
   console.log('');
   interfaceNames.forEach(function(interfaceName) {
     console.log('    ' + interfaceName);
@@ -167,9 +169,11 @@ program.on('interfaces', function(){
 
 module.paths.push(cwd, join(cwd, 'node_modules'));
 
-program.on('require', function(mod){
+program.on('require', function(mod) {
   var abs = exists(mod) || exists(mod + '.js');
-  if (abs) mod = resolve(mod);
+  if (abs) {
+    mod = resolve(mod);
+  }
   requires.push(mod);
 });
 
@@ -190,16 +194,16 @@ Error.stackTraceLimit = Infinity; // TODO: config
 
 var reporterOptions = {};
 if (program.reporterOptions !== undefined) {
-    program.reporterOptions.split(",").forEach(function(opt) {
-        var L = opt.split("=");
-        if (L.length > 2 || L.length === 0) {
-            throw new Error("invalid reporter option '" + opt + "'");
-        } else if (L.length === 2) {
-            reporterOptions[L[0]] = L[1];
-        } else {
-            reporterOptions[L[0]] = true;
-        }
-    });
+  program.reporterOptions.split(',').forEach(function(opt) {
+    var L = opt.split('=');
+    if (L.length > 2 || L.length === 0) {
+      throw new Error("invalid reporter option '" + opt + "'");
+    } else if (L.length === 2) {
+      reporterOptions[L[0]] = L[1];
+    } else {
+      reporterOptions[L[0]] = true;
+    }
+  });
 }
 
 // reporter
@@ -214,37 +218,46 @@ try {
 } catch (err) {
   try {
     Reporter = require(program.reporter);
-  } catch (err) {
+  } catch (err2) {
     throw new Error('reporter "' + program.reporter + '" does not exist');
   }
 }
 
 // --no-colors
 
-if (!program.colors) mocha.useColors(false);
+if (!program.colors) {
+  mocha.useColors(false);
+}
 
 // --colors
 
-if (~process.argv.indexOf('--colors') ||
-    ~process.argv.indexOf('-c')) {
+if (~process.argv.indexOf('--colors') || ~process.argv.indexOf('-c')) {
   mocha.useColors(true);
 }
 
 // --inline-diffs
 
-if (program.inlineDiffs) mocha.useInlineDiffs(true);
+if (program.inlineDiffs) {
+  mocha.useInlineDiffs(true);
+}
 
 // --slow <ms>
 
-if (program.slow) mocha.suite.slow(program.slow);
+if (program.slow) {
+  mocha.suite.slow(program.slow);
+}
 
 // --no-timeouts
 
-if (!program.timeouts) mocha.enableTimeouts(false);
+if (!program.timeouts) {
+  mocha.enableTimeouts(false);
+}
 
 // --timeout
 
-if (program.timeout) mocha.suite.timeout(program.timeout);
+if (program.timeout) {
+  mocha.suite.timeout(program.timeout);
+}
 
 // --bail
 
@@ -252,35 +265,51 @@ mocha.suite.bail(program.bail);
 
 // --grep
 
-if (program.grep) mocha.grep(program.grep);
+if (program.grep) {
+  mocha.grep(program.grep);
+}
 
 // --fgrep
 
-if (program.fgrep) mocha.fgrep(program.fgrep);
+if (program.fgrep) {
+  mocha.fgrep(program.fgrep);
+}
 
 // --invert
 
-if (program.invert) mocha.invert();
+if (program.invert) {
+  mocha.invert();
+}
 
 // --check-leaks
 
-if (program.checkLeaks) mocha.checkLeaks();
+if (program.checkLeaks) {
+  mocha.checkLeaks();
+}
 
 // --stack-trace
 
-if(program.fullTrace) mocha.fullTrace();
+if (program.fullTrace) {
+  mocha.fullTrace();
+}
 
 // --growl
 
-if (program.growl) mocha.growl();
+if (program.growl) {
+  mocha.growl();
+}
 
 // --async-only
 
-if (program.asyncOnly) mocha.asyncOnly();
+if (program.asyncOnly) {
+  mocha.asyncOnly();
+}
 
 // --delay
 
-if (program.delay) mocha.delay();
+if (program.delay) {
+  mocha.delay();
+}
 
 // --globals
 
@@ -288,17 +317,21 @@ mocha.globals(globals);
 
 // --retries
 
-if (program.retries) mocha.suite.retries(program.retries);
+if (program.retries) {
+  mocha.suite.retries(program.retries);
+}
 
 // custom compiler support
 
 var extensions = ['js'];
 program.compilers.forEach(function(c) {
-  var idx = c.indexOf(':')
-    , ext = c.slice(0, idx)
-    , mod = c.slice(idx + 1);
+  var idx = c.indexOf(':');
+  var ext = c.slice(0, idx);
+  var mod = c.slice(idx + 1);
 
-  if (mod[0] == '.') mod = join(process.cwd(), mod);
+  if (mod[0] === '.') {
+    mod = join(process.cwd(), mod);
+  }
   require(mod);
   extensions.push(ext);
   program.watchExtensions.push(ext);
@@ -314,21 +347,40 @@ requires.forEach(function(mod) {
 
 mocha.ui(program.ui);
 
-//args
+// args
 
 var args = program.args;
 
 // default files to test/*.{js,coffee}
 
-if (!args.length) args.push('test');
+if (!args.length) {
+  args.push('test');
+}
+
+args.forEach(function(arg) {
+  var newFiles;
+  try {
+    newFiles = utils.lookupFiles(arg, extensions, program.recursive);
+  } catch (err) {
+    if (err.message.indexOf('cannot resolve path') === 0) {
+      console.error('Warning: Could not find any test files matching pattern: ' + arg);
+      return;
+    }
 
-args.forEach(function(arg){
-  files = files.concat(utils.lookupFiles(arg, extensions, program.recursive));
+    throw err;
+  }
+
+  files = files.concat(newFiles);
 });
 
+if (!files.length) {
+  console.error('No test files found');
+  process.exit(1);
+}
+
 // resolve
 
-files = files.map(function(path){
+files = files.map(function(path) {
   return resolve(path);
 });
 
@@ -339,54 +391,58 @@ if (program.sort) {
 // --watch
 
 var runner;
+var loadAndRun;
+var purge;
+var rerun;
+
 if (program.watch) {
   console.log();
   hideCursor();
-  process.on('SIGINT', function(){
+  process.on('SIGINT', function() {
     showCursor();
     console.log('\n');
-    process.exit();
+    process.exit(130);
   });
 
-
   var watchFiles = utils.files(cwd, [ 'js' ].concat(program.watchExtensions));
   var runAgain = false;
 
-  function loadAndRun() {
+  loadAndRun = function loadAndRun() {
     try {
       mocha.files = files;
       runAgain = false;
-      runner = mocha.run(function(){
+      runner = mocha.run(function() {
         runner = null;
         if (runAgain) {
           rerun();
         }
       });
-    } catch(e) {
+    } catch (e) {
       console.log(e.stack);
     }
-  }
+  };
 
-  function purge() {
-    watchFiles.forEach(function(file){
+  purge = function purge() {
+    watchFiles.forEach(function(file) {
       delete require.cache[file];
     });
-  }
+  };
 
   loadAndRun();
 
-  function rerun() {
+  rerun = function rerun() {
     purge();
-    stop()
-    if (!program.grep)
+    stop();
+    if (!program.grep) {
       mocha.grep(null);
+    }
     mocha.suite = mocha.suite.clone();
-    mocha.suite.ctx = new Mocha.Context;
+    mocha.suite.ctx = new Mocha.Context();
     mocha.ui(program.ui);
     loadAndRun();
-  }
+  };
 
-  utils.watch(watchFiles, function(){
+  utils.watch(watchFiles, function() {
     runAgain = true;
     if (runner) {
       runner.abort();
@@ -394,18 +450,17 @@ if (program.watch) {
       rerun();
     }
   });
-
 } else {
-
 // load
 
   mocha.files = files;
   runner = mocha.run(program.exit ? exit : exitLater);
-
 }
 
 function exitLater(code) {
-  process.on('exit', function() { process.exit(code) })
+  process.on('exit', function() {
+    process.exit(Math.min(code, 255));
+  });
 }
 
 function exit(code) {
@@ -413,13 +468,15 @@ function exit(code) {
   // https://github.com/joyent/node/issues/6247 is just one bug example
   // https://github.com/visionmedia/mocha/issues/333 has a good discussion
   function done() {
-    if (!(draining--)) process.exit(code);
+    if (!(draining--)) {
+      process.exit(Math.min(code, 255));
+    }
   }
 
   var draining = 0;
   var streams = [process.stdout, process.stderr];
 
-  streams.forEach(function(stream){
+  streams.forEach(function(stream) {
     // submit empty write request and wait for completion
     draining += 1;
     stream.write('', done);
@@ -428,7 +485,14 @@ function exit(code) {
   done();
 }
 
-process.on('SIGINT', function() { runner.abort(); })
+process.on('SIGINT', function() {
+  runner.abort();
+
+  // This is a hack:
+  // Instead of `process.exit(130)`, set runner.failures to 130 (exit code for SIGINT)
+  // The amount of failures will be emitted as error code later
+  runner.failures = 130;
+});
 
 /**
  * Parse list.
@@ -442,7 +506,7 @@ function list(str) {
  * Hide the cursor.
  */
 
-function hideCursor(){
+function hideCursor() {
   process.stdout.write('\u001b[?25l');
 }
 
@@ -450,7 +514,7 @@ function hideCursor(){
  * Show the cursor.
  */
 
-function showCursor(){
+function showCursor() {
   process.stdout.write('\u001b[?25h');
 }
 
@@ -468,11 +532,11 @@ function stop() {
  */
 
 function play(arr, interval) {
-  var len = arr.length
-    , interval = interval || 100
-    , i = 0;
+  var len = arr.length;
+  interval = interval || 100;
+  var i = 0;
 
-  play.timer = setInterval(function(){
+  play.timer = setInterval(function() {
     var str = arr[i++ % len];
     process.stdout.write('\u001b[0G' + str);
   }, interval);
diff --git a/bin/mocha b/bin/mocha
index 99bc18ae4d..0c16f0ee94 100755
--- a/bin/mocha
+++ b/bin/mocha
@@ -5,17 +5,16 @@
  * when found, before invoking the "real" _mocha(1) executable.
  */
 
-var spawn = require('child_process').spawn,
-  path = require('path'),
-  fs = require('fs'),
-  getOptions = require('./options'),
-  args = [path.join(__dirname, '_mocha')];
+var spawn = require('child_process').spawn;
+var path = require('path');
+var getOptions = require('./options');
+var args = [path.join(__dirname, '_mocha')];
 
 // Load mocha.opts into process.argv
 // Must be loaded here to handle node-specific options
 getOptions();
 
-process.argv.slice(2).forEach(function(arg){
+process.argv.slice(2).forEach(function(arg) {
   var flag = arg.split('=')[0];
 
   switch (flag) {
@@ -26,6 +25,7 @@ process.argv.slice(2).forEach(function(arg){
     case 'debug':
     case '--debug':
     case '--debug-brk':
+    case '--inspect':
       args.unshift(arg);
       args.push('--no-timeouts');
       break;
@@ -46,19 +46,26 @@ process.argv.slice(2).forEach(function(arg){
       args.unshift(arg);
       break;
     default:
-      if (0 == arg.indexOf('--harmony')) args.unshift(arg);
-      else if (0 == arg.indexOf('--trace')) args.unshift(arg);
-      else if (0 == arg.indexOf('--icu-data-dir')) args.unshift(arg);
-      else if (0 == arg.indexOf('--max-old-space-size')) args.unshift(arg);
-      else if (0 == arg.indexOf('--preserve-symlinks')) args.unshift(arg);
-      else args.push(arg);
+      if (arg.indexOf('--harmony') === 0) {
+        args.unshift(arg);
+      } else if (arg.indexOf('--trace') === 0) {
+        args.unshift(arg);
+      } else if (arg.indexOf('--icu-data-dir') === 0) {
+        args.unshift(arg);
+      } else if (arg.indexOf('--max-old-space-size') === 0) {
+        args.unshift(arg);
+      } else if (arg.indexOf('--preserve-symlinks') === 0) {
+        args.unshift(arg);
+      } else {
+        args.push(arg);
+      }
       break;
   }
 });
 
 var proc = spawn(process.execPath, args, { stdio: 'inherit' });
-proc.on('exit', function (code, signal) {
-  process.on('exit', function(){
+proc.on('exit', function(code, signal) {
+  process.on('exit', function() {
     if (signal) {
       process.kill(process.pid, signal);
     } else {
@@ -68,7 +75,7 @@ proc.on('exit', function (code, signal) {
 });
 
 // terminate children.
-process.on('SIGINT', function () {
+process.on('SIGINT', function() {
   proc.kill('SIGINT'); // calls runner.abort()
   proc.kill('SIGTERM'); // if that didn't work, we're probably in an infinite loop, so make it die.
 });
diff --git a/browser-entry.js b/browser-entry.js
index 341a199914..789e686ae6 100644
--- a/browser-entry.js
+++ b/browser-entry.js
@@ -1,3 +1,5 @@
+/* eslint no-unused-vars: off */
+
 /**
  * Shim process.stdout.
  */
@@ -33,15 +35,17 @@ var originalOnerrorHandler = global.onerror;
  * Revert to original onerror handler if previously defined.
  */
 
-process.removeListener = function(e, fn){
-  if ('uncaughtException' == e) {
+process.removeListener = function(e, fn) {
+  if (e === 'uncaughtException') {
     if (originalOnerrorHandler) {
       global.onerror = originalOnerrorHandler;
     } else {
       global.onerror = function() {};
     }
     var i = Mocha.utils.indexOf(uncaughtExceptionHandlers, fn);
-    if (i != -1) { uncaughtExceptionHandlers.splice(i, 1); }
+    if (i !== -1) {
+      uncaughtExceptionHandlers.splice(i, 1);
+    }
   }
 };
 
@@ -49,9 +53,9 @@ process.removeListener = function(e, fn){
  * Implements uncaughtException listener.
  */
 
-process.on = function(e, fn){
-  if ('uncaughtException' == e) {
-    global.onerror = function(err, url, line){
+process.on = function(e, fn) {
+  if (e === 'uncaughtException') {
+    global.onerror = function(err, url, line) {
       fn(new Error(err + ' (' + url + ':' + line + ')'));
       return !mocha.allowUncaught;
     };
@@ -64,8 +68,8 @@ process.on = function(e, fn){
 // Ensure that this default UI does not expose its methods to the global scope.
 mocha.suite.removeAllListeners('pre-require');
 
-var immediateQueue = []
-  , immediateTimeout;
+var immediateQueue = [];
+var immediateTimeout;
 
 function timeslice() {
   var immediateStart = new Date().getTime();
@@ -96,7 +100,7 @@ Mocha.Runner.immediately = function(callback) {
  * only receive the 'message' attribute of the Error.
  */
 mocha.throwError = function(err) {
-  Mocha.utils.forEach(uncaughtExceptionHandlers, function (fn) {
+  Mocha.utils.forEach(uncaughtExceptionHandlers, function(fn) {
     fn(err);
   });
   throw err;
@@ -107,7 +111,7 @@ mocha.throwError = function(err) {
  * Normally this would happen in Mocha.prototype.loadFiles.
  */
 
-mocha.ui = function(ui){
+mocha.ui = function(ui) {
   Mocha.prototype.ui.call(this, ui);
   this.suite.emit('pre-require', global, null, this);
   return this;
@@ -117,9 +121,15 @@ mocha.ui = function(ui){
  * Setup mocha with the given setting options.
  */
 
-mocha.setup = function(opts){
-  if ('string' == typeof opts) opts = { ui: opts };
-  for (var opt in opts) this[opt](opts[opt]);
+mocha.setup = function(opts) {
+  if (typeof opts === 'string') {
+    opts = { ui: opts };
+  }
+  for (var opt in opts) {
+    if (opts.hasOwnProperty(opt)) {
+      this[opt](opts[opt]);
+    }
+  }
   return this;
 };
 
@@ -127,22 +137,30 @@ mocha.setup = function(opts){
  * Run mocha, returning the Runner.
  */
 
-mocha.run = function(fn){
+mocha.run = function(fn) {
   var options = mocha.options;
   mocha.globals('location');
 
   var query = Mocha.utils.parseQuery(global.location.search || '');
-  if (query.grep) mocha.grep(query.grep);
-  if (query.fgrep) mocha.fgrep(query.fgrep);
-  if (query.invert) mocha.invert();
+  if (query.grep) {
+    mocha.grep(query.grep);
+  }
+  if (query.fgrep) {
+    mocha.fgrep(query.fgrep);
+  }
+  if (query.invert) {
+    mocha.invert();
+  }
 
-  return Mocha.prototype.run.call(mocha, function(err){
+  return Mocha.prototype.run.call(mocha, function(err) {
     // The DOM Document is not available in Web Workers.
     var document = global.document;
     if (document && document.getElementById('mocha') && options.noHighlighting !== true) {
       Mocha.utils.highlightTags('code');
     }
-    if (fn) fn(err);
+    if (fn) {
+      fn(err);
+    }
   });
 };
 
diff --git a/karma.conf.js b/karma.conf.js
index 76e8ae631c..266fe72b7a 100644
--- a/karma.conf.js
+++ b/karma.conf.js
@@ -14,13 +14,15 @@ module.exports = function(config) {
       'mocha'
     ],
     files: [
-      'test/browser-fixtures/bdd.js',
-      'test/acceptance/*.js'
+      // we use the BDD interface for all of the tests that
+      // aren't interface-specific.
+      'test/browser-fixtures/bdd.fixture.js',
+      'test/acceptance/*.spec.js'
     ],
     exclude: [
-      'test/acceptance/http.js',
-      'test/acceptance/fs.js',
-      'test/acceptance/lookup-files.js',
+      'test/acceptance/http.spec.js',
+      'test/acceptance/fs.spec.js',
+      'test/acceptance/lookup-files.spec.js',
       'test/acceptance/require/**/*.js',
       'test/acceptance/misc/**/*.js'
     ],
@@ -108,8 +110,8 @@ module.exports = function(config) {
       cfg.sauceLabs.testName = 'Interface "' + ui + '" integration tests';
     }
     cfg.files = [
-      'test/browser-fixtures/' + ui + '.js',
-      'test/acceptance/interfaces/' + ui + '.js'
+      'test/browser-fixtures/' + ui + '.fixture.js',
+      'test/acceptance/interfaces/' + ui + '.spec.js'
     ];
   } else if (cfg.sauceLabs) {
     cfg.sauceLabs.testName = 'Unit Tests';
diff --git a/lib/interfaces/common.js b/lib/interfaces/common.js
index b367544a3f..447458487b 100644
--- a/lib/interfaces/common.js
+++ b/lib/interfaces/common.js
@@ -113,6 +113,8 @@ module.exports = function(suites, context, mocha) {
         if (typeof opts.fn === 'function') {
           opts.fn.call(suite);
           suites.shift();
+        } else if (typeof opts.fn === 'undefined' && !suite.pending) {
+          throw new Error('Suite "' + suite.fullTitle() + '" was defined but no callback was supplied. Supply a callback or explicitly skip the suite.');
         }
 
         return suite;
diff --git a/lib/interfaces/qunit.js b/lib/interfaces/qunit.js
index a2d67ef90f..22e8080e2e 100644
--- a/lib/interfaces/qunit.js
+++ b/lib/interfaces/qunit.js
@@ -50,7 +50,8 @@ module.exports = function(suite) {
       }
       return common.suite.create({
         title: title,
-        file: file
+        file: file,
+        fn: false
       });
     };
 
@@ -64,7 +65,8 @@ module.exports = function(suite) {
       }
       return common.suite.only({
         title: title,
-        file: file
+        file: file,
+        fn: false
       });
     };
 
diff --git a/lib/runnable.js b/lib/runnable.js
index d89a7dd5d7..52ee900b22 100644
--- a/lib/runnable.js
+++ b/lib/runnable.js
@@ -133,7 +133,7 @@ Runnable.prototype.enableTimeouts = function(enabled) {
  * @api public
  */
 Runnable.prototype.skip = function() {
-  throw new Pending();
+  throw new Pending('sync skip');
 };
 
 /**
@@ -298,14 +298,19 @@ Runnable.prototype.run = function(fn) {
   if (this.async) {
     this.resetTimeout();
 
+    // allows skip() to be used in an explicit async context
+    this.skip = function asyncSkip() {
+      done(new Pending('async skip call'));
+      // halt execution.  the Runnable will be marked pending
+      // by the previous call, and the uncaught handler will ignore
+      // the failure.
+      throw new Pending('async skip; aborting execution');
+    };
+
     if (this.allowUncaught) {
       return callFnAsync(this.fn);
     }
     try {
-      // allows skip() to be used in an explicit async context
-      this.skip = function() {
-        done(new Pending());
-      };
       callFnAsync(this.fn);
     } catch (err) {
       done(utils.getError(err));
diff --git a/lib/runner.js b/lib/runner.js
index f19a4060eb..145d990351 100644
--- a/lib/runner.js
+++ b/lib/runner.js
@@ -220,6 +220,10 @@ Runner.prototype.checkGlobals = function(test) {
  * @param {Error} err
  */
 Runner.prototype.fail = function(test, err) {
+  if (test.isPending()) {
+    return;
+  }
+
   ++this.failures;
   test.state = 'failed';
 
@@ -309,6 +313,8 @@ Runner.prototype.hook = function(name, fn) {
             suite.tests.forEach(function(test) {
               test.pending = true;
             });
+            // a pending hook won't be executed twice.
+            hook.pending = true;
           }
         } else {
           self.failHook(hook, err);
@@ -414,6 +420,9 @@ Runner.prototype.runTest = function(fn) {
   var self = this;
   var test = this.test;
 
+  if (!test) {
+    return;
+  }
   if (this.asyncOnly) {
     test.asyncOnly = true;
   }
@@ -695,8 +704,8 @@ Runner.prototype.uncaught = function(err) {
 
   runnable.clearTimeout();
 
-  // Ignore errors if complete
-  if (runnable.state) {
+  // Ignore errors if complete or pending
+  if (runnable.state || runnable.isPending()) {
     return;
   }
   this.fail(runnable, err);
@@ -892,7 +901,7 @@ function hasOnly(suite) {
 function filterLeaks(ok, globals) {
   return filter(globals, function(key) {
     // Firefox and Chrome exposes iframes as index inside the window object
-    if (/^d+/.test(key)) {
+    if (/^\d+/.test(key)) {
       return false;
     }
 
diff --git a/mocha.js b/mocha.js
index c9224e3b92..3ca0ae9e67 100644
--- a/mocha.js
+++ b/mocha.js
@@ -1,5 +1,7 @@
 (function e(t,n,r){function s(o,u){if(!n[o]){if(!t[o]){var a=typeof require=="function"&&require;if(!u&&a)return a(o,!0);if(i)return i(o,!0);var f=new Error("Cannot find module '"+o+"'");throw f.code="MODULE_NOT_FOUND",f}var l=n[o]={exports:{}};t[o][0].call(l.exports,function(e){var n=t[o][1][e];return s(n?n:e)},l,l.exports,e,t,n,r)}return n[o].exports}var i=typeof require=="function"&&require;for(var o=0;o<r.length;o++)s(r[o]);return s})({1:[function(require,module,exports){
 (function (process,global){
+/* eslint no-unused-vars: off */
+
 /**
  * Shim process.stdout.
  */
@@ -35,15 +37,17 @@ var originalOnerrorHandler = global.onerror;
  * Revert to original onerror handler if previously defined.
  */
 
-process.removeListener = function(e, fn){
-  if ('uncaughtException' == e) {
+process.removeListener = function(e, fn) {
+  if (e === 'uncaughtException') {
     if (originalOnerrorHandler) {
       global.onerror = originalOnerrorHandler;
     } else {
       global.onerror = function() {};
     }
     var i = Mocha.utils.indexOf(uncaughtExceptionHandlers, fn);
-    if (i != -1) { uncaughtExceptionHandlers.splice(i, 1); }
+    if (i !== -1) {
+      uncaughtExceptionHandlers.splice(i, 1);
+    }
   }
 };
 
@@ -51,9 +55,9 @@ process.removeListener = function(e, fn){
  * Implements uncaughtException listener.
  */
 
-process.on = function(e, fn){
-  if ('uncaughtException' == e) {
-    global.onerror = function(err, url, line){
+process.on = function(e, fn) {
+  if (e === 'uncaughtException') {
+    global.onerror = function(err, url, line) {
       fn(new Error(err + ' (' + url + ':' + line + ')'));
       return !mocha.allowUncaught;
     };
@@ -66,8 +70,8 @@ process.on = function(e, fn){
 // Ensure that this default UI does not expose its methods to the global scope.
 mocha.suite.removeAllListeners('pre-require');
 
-var immediateQueue = []
-  , immediateTimeout;
+var immediateQueue = [];
+var immediateTimeout;
 
 function timeslice() {
   var immediateStart = new Date().getTime();
@@ -98,7 +102,7 @@ Mocha.Runner.immediately = function(callback) {
  * only receive the 'message' attribute of the Error.
  */
 mocha.throwError = function(err) {
-  Mocha.utils.forEach(uncaughtExceptionHandlers, function (fn) {
+  Mocha.utils.forEach(uncaughtExceptionHandlers, function(fn) {
     fn(err);
   });
   throw err;
@@ -109,7 +113,7 @@ mocha.throwError = function(err) {
  * Normally this would happen in Mocha.prototype.loadFiles.
  */
 
-mocha.ui = function(ui){
+mocha.ui = function(ui) {
   Mocha.prototype.ui.call(this, ui);
   this.suite.emit('pre-require', global, null, this);
   return this;
@@ -119,9 +123,15 @@ mocha.ui = function(ui){
  * Setup mocha with the given setting options.
  */
 
-mocha.setup = function(opts){
-  if ('string' == typeof opts) opts = { ui: opts };
-  for (var opt in opts) this[opt](opts[opt]);
+mocha.setup = function(opts) {
+  if (typeof opts === 'string') {
+    opts = { ui: opts };
+  }
+  for (var opt in opts) {
+    if (opts.hasOwnProperty(opt)) {
+      this[opt](opts[opt]);
+    }
+  }
   return this;
 };
 
@@ -129,22 +139,30 @@ mocha.setup = function(opts){
  * Run mocha, returning the Runner.
  */
 
-mocha.run = function(fn){
+mocha.run = function(fn) {
   var options = mocha.options;
   mocha.globals('location');
 
   var query = Mocha.utils.parseQuery(global.location.search || '');
-  if (query.grep) mocha.grep(query.grep);
-  if (query.fgrep) mocha.fgrep(query.fgrep);
-  if (query.invert) mocha.invert();
+  if (query.grep) {
+    mocha.grep(query.grep);
+  }
+  if (query.fgrep) {
+    mocha.fgrep(query.fgrep);
+  }
+  if (query.invert) {
+    mocha.invert();
+  }
 
-  return Mocha.prototype.run.call(mocha, function(err){
+  return Mocha.prototype.run.call(mocha, function(err) {
     // The DOM Document is not available in Web Workers.
     var document = global.document;
     if (document && document.getElementById('mocha') && options.noHighlighting !== true) {
       Mocha.utils.highlightTags('code');
     }
-    if (fn) fn(err);
+    if (fn) {
+      fn(err);
+    }
   });
 };
 
diff --git a/scripts/travis-before-install.sh b/scripts/travis-before-install.sh
index c725d38948..9913070ae9 100755
--- a/scripts/travis-before-install.sh
+++ b/scripts/travis-before-install.sh
@@ -2,4 +2,4 @@
 
 npm install --production
 # this avoids our mocha.opts (and thus devDependencies) in a roundabout way
-./bin/mocha --opts /dev/null --reporter spec test/sanity/sanity.js
+./bin/mocha --opts /dev/null --reporter spec test/sanity/sanity.spec.js
diff --git a/test/acceptance/context.js b/test/acceptance/context.spec.js
similarity index 100%
rename from test/acceptance/context.js
rename to test/acceptance/context.spec.js
diff --git a/test/acceptance/duration.js b/test/acceptance/duration.spec.js
similarity index 100%
rename from test/acceptance/duration.js
rename to test/acceptance/duration.spec.js
diff --git a/test/acceptance/fs.js b/test/acceptance/fs.spec.js
similarity index 100%
rename from test/acceptance/fs.js
rename to test/acceptance/fs.spec.js
diff --git a/test/acceptance/glob/glob.sh b/test/acceptance/glob/glob.sh
index a2b8c6fea2..823ba07fb9 100755
--- a/test/acceptance/glob/glob.sh
+++ b/test/acceptance/glob/glob.sh
@@ -22,11 +22,22 @@ cat /tmp/mocha-glob.txt | grep -q -F '["end",{"suites":1,"tests":1,"passes":1,"p
     exit 1
 }
 
-cat /tmp/mocha-glob.txt | grep -q -F 'cannot resolve path' || {
+cat /tmp/mocha-glob.txt | grep -q -F 'Could not find any test files matching pattern' || {
     echo Globbing './*-none.js' in `pwd` should match no files and run no tests.
     exit 1
 }
 
+../../../bin/mocha -R json-stream  ./*.js ./*-none.js >& /tmp/mocha-glob.txt || {
+    echo Globbing ./*.js ./*-none.js in `pwd` failed.
+    exit 1
+}
+
+cat /tmp/mocha-glob.txt | grep -q -F '["end",{"suites":1,"tests":1,"passes":1,"pending":0,"failures":0,' &&
+cat /tmp/mocha-glob.txt | grep -q -F 'Could not find any test files matching pattern' || {
+    echo Globbing ./*.js ./*-none.js in `pwd` should match glob.js with one test inside and display one warning for the non-existing file.
+    exit 1
+}
+
 # Globbing in windows command-shell differs completely from unix-style globbing.
 # In bash, the shell expands globs and passes the result to executables.
 # In windows, the shell passes globs unexpanded, executables do expansion if they support it.
@@ -47,7 +58,7 @@ cat /tmp/mocha-glob.txt | grep -q -F '["end",{"suites":1,"tests":1,"passes":1,"p
     exit 1
 }
 
-cat /tmp/mocha-glob.txt | grep -q -F 'cannot resolve path' || {
+cat /tmp/mocha-glob.txt | grep -q -F 'Could not find any test files matching pattern' || {
     echo Globbing './*-none.js' in `pwd` should match no files and run no tests.
     exit 1
 }
diff --git a/test/acceptance/glob/glob.js b/test/acceptance/glob/glob.spec.js
similarity index 100%
rename from test/acceptance/glob/glob.js
rename to test/acceptance/glob/glob.spec.js
diff --git a/test/acceptance/globals.js b/test/acceptance/globals.spec.js
similarity index 100%
rename from test/acceptance/globals.js
rename to test/acceptance/globals.spec.js
diff --git a/test/acceptance/http.js b/test/acceptance/http.spec.js
similarity index 100%
rename from test/acceptance/http.js
rename to test/acceptance/http.spec.js
diff --git a/test/acceptance/interfaces/bdd.js b/test/acceptance/interfaces/bdd.spec.js
similarity index 100%
rename from test/acceptance/interfaces/bdd.js
rename to test/acceptance/interfaces/bdd.spec.js
diff --git a/test/acceptance/interfaces/exports.js b/test/acceptance/interfaces/exports.spec.js
similarity index 100%
rename from test/acceptance/interfaces/exports.js
rename to test/acceptance/interfaces/exports.spec.js
diff --git a/test/acceptance/interfaces/qunit.js b/test/acceptance/interfaces/qunit.spec.js
similarity index 100%
rename from test/acceptance/interfaces/qunit.js
rename to test/acceptance/interfaces/qunit.spec.js
diff --git a/test/acceptance/interfaces/tdd.js b/test/acceptance/interfaces/tdd.spec.js
similarity index 100%
rename from test/acceptance/interfaces/tdd.js
rename to test/acceptance/interfaces/tdd.spec.js
diff --git a/test/acceptance/lookup-files.js b/test/acceptance/lookup-files.spec.js
similarity index 100%
rename from test/acceptance/lookup-files.js
rename to test/acceptance/lookup-files.spec.js
diff --git a/test/acceptance/misc/exit.js b/test/acceptance/misc/exit.spec.js
similarity index 100%
rename from test/acceptance/misc/exit.js
rename to test/acceptance/misc/exit.spec.js
diff --git a/test/acceptance/misc/many.js b/test/acceptance/misc/many.spec.js
similarity index 100%
rename from test/acceptance/misc/many.js
rename to test/acceptance/misc/many.spec.js
diff --git a/test/acceptance/misc/nontty.js b/test/acceptance/misc/nontty.spec.js
similarity index 100%
rename from test/acceptance/misc/nontty.js
rename to test/acceptance/misc/nontty.spec.js
diff --git a/test/acceptance/misc/only/bdd-require.js b/test/acceptance/misc/only/bdd-require.spec.js
similarity index 100%
rename from test/acceptance/misc/only/bdd-require.js
rename to test/acceptance/misc/only/bdd-require.spec.js
diff --git a/test/acceptance/misc/only/bdd.js b/test/acceptance/misc/only/bdd.spec.js
similarity index 100%
rename from test/acceptance/misc/only/bdd.js
rename to test/acceptance/misc/only/bdd.spec.js
diff --git a/test/acceptance/misc/only/global/bdd.js b/test/acceptance/misc/only/global/bdd.spec.js
similarity index 100%
rename from test/acceptance/misc/only/global/bdd.js
rename to test/acceptance/misc/only/global/bdd.spec.js
diff --git a/test/acceptance/misc/only/global/qunit.js b/test/acceptance/misc/only/global/qunit.spec.js
similarity index 100%
rename from test/acceptance/misc/only/global/qunit.js
rename to test/acceptance/misc/only/global/qunit.spec.js
diff --git a/test/acceptance/misc/only/global/tdd.js b/test/acceptance/misc/only/global/tdd.spec.js
similarity index 100%
rename from test/acceptance/misc/only/global/tdd.js
rename to test/acceptance/misc/only/global/tdd.spec.js
diff --git a/test/acceptance/misc/only/qunit.js b/test/acceptance/misc/only/qunit.spec.js
similarity index 100%
rename from test/acceptance/misc/only/qunit.js
rename to test/acceptance/misc/only/qunit.spec.js
diff --git a/test/acceptance/misc/only/tdd.js b/test/acceptance/misc/only/tdd.spec.js
similarity index 100%
rename from test/acceptance/misc/only/tdd.js
rename to test/acceptance/misc/only/tdd.spec.js
diff --git a/test/acceptance/overspecified-async.js b/test/acceptance/overspecified-async.spec.js
similarity index 100%
rename from test/acceptance/overspecified-async.js
rename to test/acceptance/overspecified-async.spec.js
diff --git a/test/acceptance/require/require.js b/test/acceptance/require/require.spec.js
similarity index 100%
rename from test/acceptance/require/require.js
rename to test/acceptance/require/require.spec.js
diff --git a/test/acceptance/required-tokens.js b/test/acceptance/required-tokens.spec.js
similarity index 100%
rename from test/acceptance/required-tokens.js
rename to test/acceptance/required-tokens.spec.js
diff --git a/test/acceptance/root.js b/test/acceptance/root.spec.js
similarity index 100%
rename from test/acceptance/root.js
rename to test/acceptance/root.spec.js
diff --git a/test/acceptance/throw.js b/test/acceptance/throw.spec.js
similarity index 100%
rename from test/acceptance/throw.js
rename to test/acceptance/throw.spec.js
diff --git a/test/acceptance/timeout.js b/test/acceptance/timeout.spec.js
similarity index 100%
rename from test/acceptance/timeout.js
rename to test/acceptance/timeout.spec.js
diff --git a/test/acceptance/utils.js b/test/acceptance/utils.spec.js
similarity index 100%
rename from test/acceptance/utils.js
rename to test/acceptance/utils.spec.js
diff --git a/test/browser-fixtures/bdd.js b/test/browser-fixtures/bdd.fixture.js
similarity index 100%
rename from test/browser-fixtures/bdd.js
rename to test/browser-fixtures/bdd.fixture.js
diff --git a/test/browser-fixtures/exports.js b/test/browser-fixtures/exports.fixture.js
similarity index 100%
rename from test/browser-fixtures/exports.js
rename to test/browser-fixtures/exports.fixture.js
diff --git a/test/browser-fixtures/qunit.js b/test/browser-fixtures/qunit.fixture.js
similarity index 100%
rename from test/browser-fixtures/qunit.js
rename to test/browser-fixtures/qunit.fixture.js
diff --git a/test/browser-fixtures/tdd.js b/test/browser-fixtures/tdd.fixture.js
similarity index 100%
rename from test/browser-fixtures/tdd.js
rename to test/browser-fixtures/tdd.fixture.js
diff --git a/test/browser/array.js b/test/browser/array.spec.js
similarity index 100%
rename from test/browser/array.js
rename to test/browser/array.spec.js
diff --git a/test/browser/grep.js b/test/browser/grep.spec.js
similarity index 100%
rename from test/browser/grep.js
rename to test/browser/grep.spec.js
diff --git a/test/browser/large.js b/test/browser/large.spec.js
similarity index 100%
rename from test/browser/large.js
rename to test/browser/large.spec.js
diff --git a/test/browser/multiple-done.js b/test/browser/multiple-done.spec.js
similarity index 100%
rename from test/browser/multiple-done.js
rename to test/browser/multiple-done.spec.js
diff --git a/test/browser/opts.js b/test/browser/opts.spec.js
similarity index 100%
rename from test/browser/opts.js
rename to test/browser/opts.spec.js
diff --git a/test/browser/stack-trace.js b/test/browser/stack-trace.spec.js
similarity index 100%
rename from test/browser/stack-trace.js
rename to test/browser/stack-trace.spec.js
diff --git a/test/browser/ui.js b/test/browser/ui.spec.js
similarity index 100%
rename from test/browser/ui.js
rename to test/browser/ui.spec.js
diff --git a/test/color.js b/test/color.spec.js
similarity index 100%
rename from test/color.js
rename to test/color.spec.js
diff --git a/test/grep.js b/test/grep.spec.js
similarity index 100%
rename from test/grep.js
rename to test/grep.spec.js
diff --git a/test/hook.async.js b/test/hook-async.spec.js
similarity index 100%
rename from test/hook.async.js
rename to test/hook-async.spec.js
diff --git a/test/hook.sync.nested.js b/test/hook-sync-nested.spec.js
similarity index 100%
rename from test/hook.sync.nested.js
rename to test/hook-sync-nested.spec.js
diff --git a/test/hook.sync.js b/test/hook-sync.spec.js
similarity index 100%
rename from test/hook.sync.js
rename to test/hook-sync.spec.js
diff --git a/test/hook.timeout.js b/test/hook-timeout.spec.js
similarity index 100%
rename from test/hook.timeout.js
rename to test/hook-timeout.spec.js
diff --git a/test/http.meta.2.js b/test/http-meta-2.spec.js
similarity index 100%
rename from test/http.meta.2.js
rename to test/http-meta-2.spec.js
diff --git a/test/http.meta.js b/test/http-meta.spec.js
similarity index 100%
rename from test/http.meta.js
rename to test/http-meta.spec.js
diff --git a/test/integration/diffs.js b/test/integration/diffs.spec.js
similarity index 95%
rename from test/integration/diffs.js
rename to test/integration/diffs.spec.js
index 111b6f2042..b779b84ada 100644
--- a/test/integration/diffs.js
+++ b/test/integration/diffs.spec.js
@@ -17,7 +17,7 @@ describe('diffs', function() {
   var diffs, expected;
 
   before(function(done) {
-    run('diffs/diffs.js', ['-C'], function(err, res) {
+    run('diffs/diffs.fixture.js', ['-C'], function(err, res) {
       expected = getExpectedOutput();
       diffs = getDiffs(res.output);
       done(err);
diff --git a/test/integration/fixtures/cascade.js b/test/integration/fixtures/cascade.fixture.js
similarity index 100%
rename from test/integration/fixtures/cascade.js
rename to test/integration/fixtures/cascade.fixture.js
diff --git a/test/integration/fixtures/diffs/diffs.js b/test/integration/fixtures/diffs/diffs.fixture.js
similarity index 100%
rename from test/integration/fixtures/diffs/diffs.js
rename to test/integration/fixtures/diffs/diffs.fixture.js
diff --git a/test/integration/fixtures/hooks/after.hook.async.error.js b/test/integration/fixtures/hooks/after-hook-async-error.fixture.js
similarity index 100%
rename from test/integration/fixtures/hooks/after.hook.async.error.js
rename to test/integration/fixtures/hooks/after-hook-async-error.fixture.js
diff --git a/test/integration/fixtures/hooks/after.hook.error.js b/test/integration/fixtures/hooks/after-hook-error.fixture.js
similarity index 100%
rename from test/integration/fixtures/hooks/after.hook.error.js
rename to test/integration/fixtures/hooks/after-hook-error.fixture.js
diff --git a/test/integration/fixtures/hooks/afterEach.hook.async.error.js b/test/integration/fixtures/hooks/afterEach-hook-async-error.fixture.js
similarity index 100%
rename from test/integration/fixtures/hooks/afterEach.hook.async.error.js
rename to test/integration/fixtures/hooks/afterEach-hook-async-error.fixture.js
diff --git a/test/integration/fixtures/hooks/afterEach.hook.error.js b/test/integration/fixtures/hooks/afterEach-hook-error.fixture.js
similarity index 100%
rename from test/integration/fixtures/hooks/afterEach.hook.error.js
rename to test/integration/fixtures/hooks/afterEach-hook-error.fixture.js
diff --git a/test/integration/fixtures/hooks/before.hook.async.error.tip.js b/test/integration/fixtures/hooks/before-hook-async-error-tip.fixture.js
similarity index 100%
rename from test/integration/fixtures/hooks/before.hook.async.error.tip.js
rename to test/integration/fixtures/hooks/before-hook-async-error-tip.fixture.js
diff --git a/test/integration/fixtures/hooks/before.hook.async.error.js b/test/integration/fixtures/hooks/before-hook-async-error.fixture.js
similarity index 100%
rename from test/integration/fixtures/hooks/before.hook.async.error.js
rename to test/integration/fixtures/hooks/before-hook-async-error.fixture.js
diff --git a/test/integration/fixtures/hooks/before.hook.error.tip.js b/test/integration/fixtures/hooks/before-hook-error-tip.fixture.js
similarity index 100%
rename from test/integration/fixtures/hooks/before.hook.error.tip.js
rename to test/integration/fixtures/hooks/before-hook-error-tip.fixture.js
diff --git a/test/integration/fixtures/hooks/before.hook.error.js b/test/integration/fixtures/hooks/before-hook-error.fixture.js
similarity index 100%
rename from test/integration/fixtures/hooks/before.hook.error.js
rename to test/integration/fixtures/hooks/before-hook-error.fixture.js
diff --git a/test/integration/fixtures/hooks/beforeEach.hook.async.error.js b/test/integration/fixtures/hooks/beforeEach-hook-async-error.fixture.js
similarity index 100%
rename from test/integration/fixtures/hooks/beforeEach.hook.async.error.js
rename to test/integration/fixtures/hooks/beforeEach-hook-async-error.fixture.js
diff --git a/test/integration/fixtures/hooks/beforeEach.hook.error.js b/test/integration/fixtures/hooks/beforeEach-hook-error.fixture.js
similarity index 100%
rename from test/integration/fixtures/hooks/beforeEach.hook.error.js
rename to test/integration/fixtures/hooks/beforeEach-hook-error.fixture.js
diff --git a/test/integration/fixtures/hooks/multiple.hook.async.error.js b/test/integration/fixtures/hooks/multiple-hook-async-error.fixture.js
similarity index 100%
rename from test/integration/fixtures/hooks/multiple.hook.async.error.js
rename to test/integration/fixtures/hooks/multiple-hook-async-error.fixture.js
diff --git a/test/integration/fixtures/hooks/multiple.hook.error.js b/test/integration/fixtures/hooks/multiple-hook-error.fixture.js
similarity index 100%
rename from test/integration/fixtures/hooks/multiple.hook.error.js
rename to test/integration/fixtures/hooks/multiple-hook-error.fixture.js
diff --git a/test/integration/fixtures/multiple.done.before.js b/test/integration/fixtures/multiple-done-before.fixture.js
similarity index 100%
rename from test/integration/fixtures/multiple.done.before.js
rename to test/integration/fixtures/multiple-done-before.fixture.js
diff --git a/test/integration/fixtures/multiple.done.beforeEach.js b/test/integration/fixtures/multiple-done-beforeEach.fixture.js
similarity index 100%
rename from test/integration/fixtures/multiple.done.beforeEach.js
rename to test/integration/fixtures/multiple-done-beforeEach.fixture.js
diff --git a/test/integration/fixtures/multiple.done.specs.js b/test/integration/fixtures/multiple-done-specs.fixture.js
similarity index 100%
rename from test/integration/fixtures/multiple.done.specs.js
rename to test/integration/fixtures/multiple-done-specs.fixture.js
diff --git a/test/integration/fixtures/multiple.done.js b/test/integration/fixtures/multiple-done.fixture.js
similarity index 100%
rename from test/integration/fixtures/multiple.done.js
rename to test/integration/fixtures/multiple-done.fixture.js
diff --git a/test/integration/fixtures/options/async-only.async.js b/test/integration/fixtures/options/async-only-async.fixture.js
similarity index 100%
rename from test/integration/fixtures/options/async-only.async.js
rename to test/integration/fixtures/options/async-only-async.fixture.js
diff --git a/test/integration/fixtures/options/async-only.sync.js b/test/integration/fixtures/options/async-only-sync.fixture.js
similarity index 100%
rename from test/integration/fixtures/options/async-only.sync.js
rename to test/integration/fixtures/options/async-only-sync.fixture.js
diff --git a/test/integration/fixtures/options/bail.js b/test/integration/fixtures/options/bail.fixture.js
similarity index 100%
rename from test/integration/fixtures/options/bail.js
rename to test/integration/fixtures/options/bail.fixture.js
diff --git a/test/integration/fixtures/options/delay-fail.js b/test/integration/fixtures/options/delay-fail.fixture.js
similarity index 100%
rename from test/integration/fixtures/options/delay-fail.js
rename to test/integration/fixtures/options/delay-fail.fixture.js
diff --git a/test/integration/fixtures/options/delay.js b/test/integration/fixtures/options/delay.fixture.js
similarity index 62%
rename from test/integration/fixtures/options/delay.js
rename to test/integration/fixtures/options/delay.fixture.js
index 32b8f99383..a8bf2d4112 100644
--- a/test/integration/fixtures/options/delay.js
+++ b/test/integration/fixtures/options/delay.fixture.js
@@ -1,13 +1,8 @@
 var assert = require('assert');
 var delay  = 500;
-var start  = new Date().getTime();
 
 setTimeout(function() {
   describe('delayed execution', function() {
-    it('should have waited ' + delay + 'ms to run this suite', function() {
-      assert(new Date().getTime() - delay >= start);
-    });
-
     it('should have no effect if attempted twice in the same suite', function() {
       assert(true);
       run();
diff --git a/test/integration/fixtures/options/grep.js b/test/integration/fixtures/options/grep.fixture.js
similarity index 100%
rename from test/integration/fixtures/options/grep.js
rename to test/integration/fixtures/options/grep.fixture.js
diff --git a/test/integration/fixtures/options/only/bdd.js b/test/integration/fixtures/options/only/bdd.fixture.js
similarity index 100%
rename from test/integration/fixtures/options/only/bdd.js
rename to test/integration/fixtures/options/only/bdd.fixture.js
diff --git a/test/integration/fixtures/options/only/qunit.js b/test/integration/fixtures/options/only/qunit.fixture.js
similarity index 100%
rename from test/integration/fixtures/options/only/qunit.js
rename to test/integration/fixtures/options/only/qunit.fixture.js
diff --git a/test/integration/fixtures/options/only/tdd.js b/test/integration/fixtures/options/only/tdd.fixture.js
similarity index 100%
rename from test/integration/fixtures/options/only/tdd.js
rename to test/integration/fixtures/options/only/tdd.fixture.js
diff --git a/test/integration/fixtures/options/retries.js b/test/integration/fixtures/options/retries.fixture.js
similarity index 100%
rename from test/integration/fixtures/options/retries.js
rename to test/integration/fixtures/options/retries.fixture.js
diff --git a/test/integration/fixtures/options/sort.alpha.js b/test/integration/fixtures/options/sort-alpha.fixture.js
similarity index 100%
rename from test/integration/fixtures/options/sort.alpha.js
rename to test/integration/fixtures/options/sort-alpha.fixture.js
diff --git a/test/integration/fixtures/options/sort.beta.js b/test/integration/fixtures/options/sort-beta.fixture.js
similarity index 100%
rename from test/integration/fixtures/options/sort.beta.js
rename to test/integration/fixtures/options/sort-beta.fixture.js
diff --git a/test/integration/fixtures/passing.js b/test/integration/fixtures/passing.fixture.js
similarity index 100%
rename from test/integration/fixtures/passing.js
rename to test/integration/fixtures/passing.fixture.js
diff --git a/test/integration/fixtures/pending/skip.async.before.js b/test/integration/fixtures/pending/skip-async-before.fixture.js
similarity index 100%
rename from test/integration/fixtures/pending/skip.async.before.js
rename to test/integration/fixtures/pending/skip-async-before.fixture.js
diff --git a/test/integration/fixtures/pending/skip.async.beforeEach.js b/test/integration/fixtures/pending/skip-async-beforeEach.fixture.js
similarity index 100%
rename from test/integration/fixtures/pending/skip.async.beforeEach.js
rename to test/integration/fixtures/pending/skip-async-beforeEach.fixture.js
diff --git a/test/integration/fixtures/pending/skip.async.spec.js b/test/integration/fixtures/pending/skip-async-spec.fixture.js
similarity index 100%
rename from test/integration/fixtures/pending/skip.async.spec.js
rename to test/integration/fixtures/pending/skip-async-spec.fixture.js
diff --git a/test/integration/fixtures/pending/skip.sync.before.js b/test/integration/fixtures/pending/skip-sync-before.fixture.js
similarity index 100%
rename from test/integration/fixtures/pending/skip.sync.before.js
rename to test/integration/fixtures/pending/skip-sync-before.fixture.js
diff --git a/test/integration/fixtures/pending/skip.sync.beforeEach.js b/test/integration/fixtures/pending/skip-sync-beforeEach.fixture.js
similarity index 100%
rename from test/integration/fixtures/pending/skip.sync.beforeEach.js
rename to test/integration/fixtures/pending/skip-sync-beforeEach.fixture.js
diff --git a/test/integration/fixtures/pending/skip.sync.spec.js b/test/integration/fixtures/pending/skip-sync-spec.fixture.js
similarity index 100%
rename from test/integration/fixtures/pending/skip.sync.spec.js
rename to test/integration/fixtures/pending/skip-sync-spec.fixture.js
diff --git a/test/integration/fixtures/pending/spec.js b/test/integration/fixtures/pending/spec.fixture.js
similarity index 100%
rename from test/integration/fixtures/pending/spec.js
rename to test/integration/fixtures/pending/spec.fixture.js
diff --git a/test/integration/fixtures/regression/1794/issue-1794.js b/test/integration/fixtures/regression/1794/issue-1794.fixture.js
similarity index 100%
rename from test/integration/fixtures/regression/1794/issue-1794.js
rename to test/integration/fixtures/regression/1794/issue-1794.fixture.js
diff --git a/test/integration/fixtures/regression/issue-1327.js b/test/integration/fixtures/regression/issue-1327.fixture.js
similarity index 100%
rename from test/integration/fixtures/regression/issue-1327.js
rename to test/integration/fixtures/regression/issue-1327.fixture.js
diff --git a/test/integration/fixtures/regression/issue-1991.js b/test/integration/fixtures/regression/issue-1991.fixture.js
similarity index 100%
rename from test/integration/fixtures/regression/issue-1991.js
rename to test/integration/fixtures/regression/issue-1991.fixture.js
diff --git a/test/integration/fixtures/regression/issue-2315.js b/test/integration/fixtures/regression/issue-2315.js
new file mode 100644
index 0000000000..cdfb201059
--- /dev/null
+++ b/test/integration/fixtures/regression/issue-2315.js
@@ -0,0 +1,9 @@
+describe('issue-2315: cannot read property currentRetry of undefined', function () {
+  before(function () {
+    process.nextTick(function () {
+      throw new Error();
+    });
+  });
+
+  it('something', function () {});
+});
diff --git a/test/integration/fixtures/regression/issue-2406.js b/test/integration/fixtures/regression/issue-2406.fixture.js
similarity index 100%
rename from test/integration/fixtures/regression/issue-2406.js
rename to test/integration/fixtures/regression/issue-2406.fixture.js
diff --git a/test/integration/fixtures/regression/issue-2417.js b/test/integration/fixtures/regression/issue-2417.fixture.js
similarity index 100%
rename from test/integration/fixtures/regression/issue-2417.js
rename to test/integration/fixtures/regression/issue-2417.fixture.js
diff --git a/test/integration/fixtures/retries/async.js b/test/integration/fixtures/retries/async.fixture.js
similarity index 100%
rename from test/integration/fixtures/retries/async.js
rename to test/integration/fixtures/retries/async.fixture.js
diff --git a/test/integration/fixtures/retries/early-pass.js b/test/integration/fixtures/retries/early-pass.fixture.js
similarity index 100%
rename from test/integration/fixtures/retries/early-pass.js
rename to test/integration/fixtures/retries/early-pass.fixture.js
diff --git a/test/integration/fixtures/retries/hooks.js b/test/integration/fixtures/retries/hooks.fixture.js
similarity index 100%
rename from test/integration/fixtures/retries/hooks.js
rename to test/integration/fixtures/retries/hooks.fixture.js
diff --git a/test/integration/fixtures/retries/nested.js b/test/integration/fixtures/retries/nested.fixture.js
similarity index 100%
rename from test/integration/fixtures/retries/nested.js
rename to test/integration/fixtures/retries/nested.fixture.js
diff --git a/test/integration/fixtures/suite/suite-no-callback.fixture.js b/test/integration/fixtures/suite/suite-no-callback.fixture.js
new file mode 100644
index 0000000000..de55b358a3
--- /dev/null
+++ b/test/integration/fixtures/suite/suite-no-callback.fixture.js
@@ -0,0 +1 @@
+describe('a suite without a callback');
diff --git a/test/integration/fixtures/suite/suite-skipped-callback.fixture.js b/test/integration/fixtures/suite/suite-skipped-callback.fixture.js
new file mode 100644
index 0000000000..b30b67ee2e
--- /dev/null
+++ b/test/integration/fixtures/suite/suite-skipped-callback.fixture.js
@@ -0,0 +1 @@
+xdescribe('a pending suite with a callback', function () {});
diff --git a/test/integration/fixtures/suite/suite-skipped-no-callback.fixture.js b/test/integration/fixtures/suite/suite-skipped-no-callback.fixture.js
new file mode 100644
index 0000000000..c5bca84a47
--- /dev/null
+++ b/test/integration/fixtures/suite/suite-skipped-no-callback.fixture.js
@@ -0,0 +1 @@
+xdescribe('a pending suite without a callback');
diff --git a/test/integration/fixtures/timeout.js b/test/integration/fixtures/timeout.fixture.js
similarity index 100%
rename from test/integration/fixtures/timeout.js
rename to test/integration/fixtures/timeout.fixture.js
diff --git a/test/integration/fixtures/uncaught.hook.js b/test/integration/fixtures/uncaught-hook.fixture.js
similarity index 100%
rename from test/integration/fixtures/uncaught.hook.js
rename to test/integration/fixtures/uncaught-hook.fixture.js
diff --git a/test/integration/fixtures/uncaught.js b/test/integration/fixtures/uncaught.fixture.js
similarity index 100%
rename from test/integration/fixtures/uncaught.js
rename to test/integration/fixtures/uncaught.fixture.js
diff --git a/test/integration/hook.err.js b/test/integration/hook-err.spec.js
similarity index 86%
rename from test/integration/hook.err.js
rename to test/integration/hook-err.spec.js
index f3a16c15d1..be18721f31 100644
--- a/test/integration/hook.err.js
+++ b/test/integration/hook-err.spec.js
@@ -7,7 +7,7 @@ describe('hook error handling', function() {
   var lines;
 
   describe('before hook error', function() {
-    before(run('hooks/before.hook.error.js'));
+    before(run('hooks/before-hook-error.fixture.js'));
     it('should verify results', function() {
       assert.deepEqual(
         lines,
@@ -17,7 +17,7 @@ describe('hook error handling', function() {
   });
 
   describe('before hook error tip', function() {
-    before(run('hooks/before.hook.error.tip.js', onlyErrorTitle));
+    before(run('hooks/before-hook-error-tip.fixture.js', onlyErrorTitle));
     it('should verify results', function() {
       assert.deepEqual(
         lines,
@@ -27,7 +27,7 @@ describe('hook error handling', function() {
   });
 
   describe('before each hook error', function() {
-    before(run('hooks/beforeEach.hook.error.js'));
+    before(run('hooks/beforeEach-hook-error.fixture.js'));
     it('should verify results', function() {
       assert.deepEqual(
         lines,
@@ -37,7 +37,7 @@ describe('hook error handling', function() {
   });
 
   describe('after hook error', function() {
-    before(run('hooks/after.hook.error.js'));
+    before(run('hooks/after-hook-error.fixture.js'));
     it('should verify results', function() {
       assert.deepEqual(
         lines,
@@ -47,7 +47,7 @@ describe('hook error handling', function() {
   });
 
   describe('after each hook error', function() {
-    before(run('hooks/afterEach.hook.error.js'));
+    before(run('hooks/afterEach-hook-error.fixture.js'));
     it('should verify results', function() {
       assert.deepEqual(
         lines,
@@ -57,7 +57,7 @@ describe('hook error handling', function() {
   });
 
   describe('multiple hook errors', function() {
-    before(run('hooks/multiple.hook.error.js'));
+    before(run('hooks/multiple-hook-error.fixture.js'));
     it('should verify results', function() {
       assert.deepEqual(
         lines,
@@ -95,7 +95,7 @@ describe('hook error handling', function() {
   });
 
   describe('async - before hook error', function() {
-    before(run('hooks/before.hook.async.error.js'));
+    before(run('hooks/before-hook-async-error.fixture.js'));
     it('should verify results', function() {
       assert.deepEqual(
         lines,
@@ -105,7 +105,7 @@ describe('hook error handling', function() {
   });
 
   describe('async - before hook error tip', function() {
-    before(run('hooks/before.hook.async.error.tip.js', onlyErrorTitle));
+    before(run('hooks/before-hook-async-error-tip.fixture.js', onlyErrorTitle));
     it('should verify results', function() {
       assert.deepEqual(
         lines,
@@ -115,7 +115,7 @@ describe('hook error handling', function() {
   });
 
   describe('async - before each hook error', function() {
-    before(run('hooks/beforeEach.hook.async.error.js'));
+    before(run('hooks/beforeEach-hook-async-error.fixture.js'));
     it('should verify results', function() {
       assert.deepEqual(
         lines,
@@ -125,7 +125,7 @@ describe('hook error handling', function() {
   });
 
   describe('async - after hook error', function() {
-    before(run('hooks/after.hook.async.error.js'));
+    before(run('hooks/after-hook-async-error.fixture.js'));
     it('should verify results', function() {
       assert.deepEqual(
         lines,
@@ -135,7 +135,7 @@ describe('hook error handling', function() {
   });
 
   describe('async - after each hook error', function() {
-    before(run('hooks/afterEach.hook.async.error.js'));
+    before(run('hooks/afterEach-hook-async-error.fixture.js'));
     it('should verify results', function() {
       assert.deepEqual(
         lines,
@@ -145,7 +145,7 @@ describe('hook error handling', function() {
   });
 
   describe('async - multiple hook errors', function() {
-    before(run('hooks/multiple.hook.async.error.js'));
+    before(run('hooks/multiple-hook-async-error.fixture.js'));
     it('should verify results', function() {
       assert.deepEqual(
         lines,
diff --git a/test/integration/hooks.js b/test/integration/hooks.spec.js
similarity index 94%
rename from test/integration/hooks.js
rename to test/integration/hooks.spec.js
index acd829f7c9..7633cb5630 100644
--- a/test/integration/hooks.js
+++ b/test/integration/hooks.spec.js
@@ -5,7 +5,7 @@ var args   = [];
 
 describe('hooks', function() {
   it('are ran in correct order', function(done) {
-    run('cascade.js', args, function(err, res) {
+    run('cascade.fixture.js', args, function(err, res) {
       var lines, expected;
 
       assert(!err);
diff --git a/test/integration/multiple.done.js b/test/integration/multiple-done.spec.js
similarity index 89%
rename from test/integration/multiple.done.js
rename to test/integration/multiple-done.spec.js
index 0159e90e43..47e82dbebb 100644
--- a/test/integration/multiple.done.js
+++ b/test/integration/multiple-done.spec.js
@@ -6,7 +6,7 @@ describe('multiple calls to done()', function() {
   var res;
   describe('from a spec', function() {
     before(function(done) {
-      run('multiple.done.js', args, function(err, result) {
+      run('multiple-done.fixture.js', args, function(err, result) {
         res = result;
         done(err);
       });
@@ -27,7 +27,7 @@ describe('multiple calls to done()', function() {
 
   describe('with multiple specs', function() {
     before(function(done) {
-      run('multiple.done.specs.js', args, function(err, result) {
+      run('multiple-done-specs.fixture.js', args, function(err, result) {
         res = result;
         done(err);
       });
@@ -49,7 +49,7 @@ describe('multiple calls to done()', function() {
 
   describe('from a before hook', function() {
     before(function(done) {
-      run('multiple.done.before.js', args, function(err, result) {
+      run('multiple-done-before.fixture.js', args, function(err, result) {
         res = result;
         done(err);
       });
@@ -71,7 +71,7 @@ describe('multiple calls to done()', function() {
 
   describe('from a beforeEach hook', function() {
     before(function(done) {
-      run('multiple.done.beforeEach.js', args, function(err, result) {
+      run('multiple-done-beforeEach.fixture.js', args, function(err, result) {
         res = result;
         done(err);
       });
diff --git a/test/integration/only.js b/test/integration/only.js
deleted file mode 100644
index dc7644e5a4..0000000000
--- a/test/integration/only.js
+++ /dev/null
@@ -1,37 +0,0 @@
-var run = require('./helpers').runMochaJSON;
-var assert = require('assert');
-
-describe('.only()', function() {
-  it('should run only tests that marked as `only`', function(done) {
-    run('options/only/bdd.js', ['--ui', 'bdd'], function(err, res) {
-      assert(!err);
-      assert.equal(res.stats.pending, 0);
-      assert.equal(res.stats.passes, 11);
-      assert.equal(res.stats.failures, 0);
-      assert.equal(res.code, 0);
-      done();
-    });
-  });
-
-  it('should run only tests that marked as `only`', function(done) {
-    run('options/only/tdd.js', ['--ui', 'tdd'], function(err, res) {
-      assert(!err);
-      assert.equal(res.stats.pending, 0);
-      assert.equal(res.stats.passes, 8);
-      assert.equal(res.stats.failures, 0);
-      assert.equal(res.code, 0);
-      done();
-    });
-  });
-
-  it('should run only tests that marked as `only`', function(done) {
-    run('options/only/qunit.js', ['--ui', 'qunit'], function(err, res) {
-      assert(!err);
-      assert.equal(res.stats.pending, 0);
-      assert.equal(res.stats.passes, 5);
-      assert.equal(res.stats.failures, 0);
-      assert.equal(res.code, 0);
-      done();
-    });
-  });
-});
diff --git a/test/integration/only.spec.js b/test/integration/only.spec.js
new file mode 100644
index 0000000000..61254ce1d3
--- /dev/null
+++ b/test/integration/only.spec.js
@@ -0,0 +1,45 @@
+var run = require('./helpers').runMochaJSON;
+var assert = require('assert');
+
+describe('.only()', function() {
+  describe('bdd', function() {
+    it('should run only tests that marked as `only`', function(done) {
+      run('options/only/bdd.fixture.js', ['--ui', 'bdd'], function(err, res) {
+        assert(!err);
+        assert.equal(res.stats.pending, 0);
+        assert.equal(res.stats.passes, 11);
+        assert.equal(res.stats.failures, 0);
+        assert.equal(res.code, 0);
+        done();
+      });
+    });
+  });
+
+  describe('tdd', function() {
+    it('should run only tests that marked as `only`', function(done) {
+      run('options/only/tdd.fixture.js', ['--ui', 'tdd'], function(err, res) {
+        assert(!err);
+        assert.equal(res.stats.pending, 0);
+        assert.equal(res.stats.passes, 8);
+        assert.equal(res.stats.failures, 0);
+        assert.equal(res.code, 0);
+        done();
+      });
+    });
+  });
+
+  describe('qunit', function() {
+    it('should run only tests that marked as `only`', function(done) {
+      run('options/only/qunit.fixture.js', ['--ui', 'qunit'], function(err, res) {
+        console.log(err);
+
+        assert(!err);
+        assert.equal(res.stats.pending, 0);
+        assert.equal(res.stats.passes, 5);
+        assert.equal(res.stats.failures, 0);
+        assert.equal(res.code, 0);
+        done();
+      });
+    });
+  });
+});
diff --git a/test/integration/options.js b/test/integration/options.spec.js
similarity index 85%
rename from test/integration/options.js
rename to test/integration/options.spec.js
index 5e18ac5e71..4755647f76 100644
--- a/test/integration/options.js
+++ b/test/integration/options.spec.js
@@ -10,7 +10,7 @@ describe('options', function() {
     });
 
     it('should fail synchronous specs', function(done) {
-      run('options/async-only.sync.js', args, function(err, res) {
+      run('options/async-only-sync.fixture.js', args, function(err, res) {
         assert(!err);
         assert.equal(res.stats.pending, 0);
         assert.equal(res.stats.passes, 0);
@@ -23,7 +23,7 @@ describe('options', function() {
     });
 
     it('should allow asynchronous specs', function(done) {
-      run('options/async-only.async.js', args, function(err, res) {
+      run('options/async-only-async.fixture.js', args, function(err, res) {
         assert(!err);
         assert.equal(res.stats.pending, 0);
         assert.equal(res.stats.passes, 1);
@@ -42,7 +42,7 @@ describe('options', function() {
     });
 
     it('should stop after the first error', function(done) {
-      run('options/bail.js', args, function(err, res) {
+      run('options/bail.fixture.js', args, function(err, res) {
         assert(!err);
         assert.equal(res.stats.pending, 0);
         assert.equal(res.stats.passes, 1);
@@ -82,21 +82,21 @@ describe('options', function() {
     });
 
     it('should run the generated test suite', function(done) {
-      run('options/delay.js', args, function(err, res) {
+      run('options/delay.fixture.js', args, function(err, res) {
         assert(!err);
         assert.equal(res.stats.pending, 0);
-        assert.equal(res.stats.passes, 2);
+        assert.equal(res.stats.passes, 1);
         assert.equal(res.stats.failures, 0);
 
         assert.equal(res.passes[0].title,
-          'should have waited 500ms to run this suite');
+          'should have no effect if attempted twice in the same suite');
         assert.equal(res.code, 0);
         done();
       });
     });
 
     it('should throw an error if the test suite failed to run', function(done) {
-      run('options/delay-fail.js', args, function(err, res) {
+      run('options/delay-fail.fixture.js', args, function(err, res) {
         assert(!err);
         assert.equal(res.stats.pending, 0);
         assert.equal(res.stats.passes, 0);
@@ -113,7 +113,7 @@ describe('options', function() {
   describe('--grep', function() {
     it('runs specs matching a string', function(done) {
       args = ['--grep', 'match'];
-      run('options/grep.js', args, function(err, res) {
+      run('options/grep.fixture.js', args, function(err, res) {
         assert(!err);
         assert.equal(res.stats.pending, 0);
         assert.equal(res.stats.passes, 2);
@@ -126,7 +126,7 @@ describe('options', function() {
     describe('runs specs matching a RegExp', function() {
       it('with RegExp like strings(pattern follow by flag)', function(done) {
         args = ['--grep', '/match/i'];
-        run('options/grep.js', args, function(err, res) {
+        run('options/grep.fixture.js', args, function(err, res) {
           assert(!err);
           assert.equal(res.stats.pending, 0);
           assert.equal(res.stats.passes, 4);
@@ -138,7 +138,7 @@ describe('options', function() {
 
       it('string as pattern', function(done) {
         args = ['--grep', '.*'];
-        run('options/grep.js', args, function(err, res) {
+        run('options/grep.fixture.js', args, function(err, res) {
           assert(!err);
           assert.equal(res.stats.pending, 0);
           assert.equal(res.stats.passes, 4);
@@ -152,7 +152,7 @@ describe('options', function() {
     describe('with --invert', function() {
       it('runs specs that do not match the pattern', function(done) {
         args = ['--grep', 'fail', '--invert'];
-        run('options/grep.js', args, function(err, res) {
+        run('options/grep.fixture.js', args, function(err, res) {
           assert(!err);
           assert.equal(res.stats.pending, 0);
           assert.equal(res.stats.passes, 4);
@@ -167,7 +167,7 @@ describe('options', function() {
   describe('--retries', function() {
     it('retries after a certain threshold', function (done) {
       args = ['--retries', '3'];
-      run('options/retries.js', args, function(err, res) {
+      run('options/retries.fixture.js', args, function(err, res) {
         assert(!err);
         assert.equal(res.stats.pending, 0);
         assert.equal(res.stats.passes, 0);
diff --git a/test/integration/pending.js b/test/integration/pending.spec.js
similarity index 83%
rename from test/integration/pending.js
rename to test/integration/pending.spec.js
index 0c18ab4bc7..4d4beffc2a 100644
--- a/test/integration/pending.js
+++ b/test/integration/pending.spec.js
@@ -5,7 +5,7 @@ var args   = [];
 describe('pending', function() {
   describe('pending specs', function() {
     it('should be created by omitting a function', function(done) {
-      run('pending/spec.js', args, function(err, res) {
+      run('pending/spec.fixture.js', args, function(err, res) {
         assert(!err);
         assert.equal(res.stats.pending, 1);
         assert.equal(res.stats.passes, 0);
@@ -19,7 +19,7 @@ describe('pending', function() {
   describe('synchronous skip()', function() {
     describe('in spec', function() {
       it('should immediately skip the spec and run all others', function(done) {
-        run('pending/skip.sync.spec.js', args, function(err, res) {
+        run('pending/skip-sync-spec.fixture.js', args, function(err, res) {
           assert(!err);
           assert.equal(res.stats.pending, 1);
           assert.equal(res.stats.passes, 1);
@@ -32,7 +32,7 @@ describe('pending', function() {
 
     describe('in before', function() {
       it('should skip all suite specs', function(done) {
-        run('pending/skip.sync.before.js', args, function(err, res) {
+        run('pending/skip-sync-before.fixture.js', args, function(err, res) {
           assert(!err);
           assert.equal(res.stats.pending, 2);
           assert.equal(res.stats.passes, 0);
@@ -45,7 +45,7 @@ describe('pending', function() {
 
     describe('in beforeEach', function() {
       it('should skip all suite specs', function(done) {
-        run('pending/skip.sync.beforeEach.js', args, function(err, res) {
+        run('pending/skip-sync-beforeEach.fixture.js', args, function(err, res) {
           assert(!err);
           assert.equal(res.stats.pending, 2);
           assert.equal(res.stats.passes, 0);
@@ -60,7 +60,7 @@ describe('pending', function() {
   describe('asynchronous skip()', function() {
     describe('in spec', function() {
       it('should immediately skip the spec and run all others', function(done) {
-        run('pending/skip.async.spec.js', args, function(err, res) {
+        run('pending/skip-async-spec.fixture.js', args, function(err, res) {
           assert(!err);
           assert.equal(res.stats.pending, 1);
           assert.equal(res.stats.passes, 1);
@@ -73,7 +73,7 @@ describe('pending', function() {
 
     describe('in before', function() {
       it('should skip all suite specs', function(done) {
-        run('pending/skip.async.before.js', args, function(err, res) {
+        run('pending/skip-async-before.fixture.js', args, function(err, res) {
           assert(!err);
           assert.equal(res.stats.pending, 2);
           assert.equal(res.stats.passes, 0);
@@ -86,7 +86,7 @@ describe('pending', function() {
 
     describe('in beforeEach', function() {
       it('should skip all suite specs', function(done) {
-        run('pending/skip.sync.beforeEach.js', args, function(err, res) {
+        run('pending/skip-sync-beforeEach.fixture.js', args, function(err, res) {
           assert(!err);
           assert.equal(res.stats.pending, 2);
           assert.equal(res.stats.passes, 0);
diff --git a/test/integration/regression.js b/test/integration/regression.spec.js
similarity index 80%
rename from test/integration/regression.js
rename to test/integration/regression.spec.js
index f0762ec0e9..f2a435a34c 100644
--- a/test/integration/regression.js
+++ b/test/integration/regression.spec.js
@@ -1,4 +1,4 @@
-var assert  = require('assert');
+var assert  = require('assert');
 var fs      = require('fs');
 var path    = require('path');
 var run     = require('./helpers').runMocha;
@@ -7,7 +7,7 @@ var runJSON = require('./helpers').runMochaJSON;
 describe('regressions', function() {
   it('issue-1327: should run all 3 specs exactly once', function(done) {
     var args = [];
-    run('regression/issue-1327.js', args, function(err, res) {
+    run('regression/issue-1327.fixture.js', args, function(err, res) {
       var occurences = function(str) {
         var pattern = new RegExp(str, 'g');
         return (res.output.match(pattern) || []).length;
@@ -33,7 +33,7 @@ describe('regressions', function() {
   it('issue-1794: Can\'t --require custom UI and use it', function(done) {
     var simpleUiPath = path.join(__dirname, 'fixtures', 'regression', '1794', 'simple-ui.js');
     var args = ['--require', simpleUiPath, '--ui', 'simple-ui'];
-    run('regression/1794/issue-1794.js', args, function(err, res) {
+    run('regression/1794/issue-1794.fixture.js', args, function(err, res) {
       assert.equal(res.code, 0, 'Custom UI should be loaded');
       done();
     });
@@ -43,7 +43,7 @@ describe('regressions', function() {
     // on a modern MBP takes ±5 seconds on node 4.0, but on older laptops with node 0.12 ±40 seconds.
     // Could easily take longer on even weaker machines (Travis-CI containers for example).
     this.timeout(120000);
-    run('regression/issue-1991.js', [], function(err, res) {
+    run('regression/issue-1991.fixture.js', [], function(err, res) {
       assert.equal(/process out of memory/.test(res.output), false, 'fixture\'s process out of memory!');
       assert.equal(res.code, 0, 'Runnable fn (it/before[Each]/after[Each]) references should be deleted to avoid memory leaks');
       done();
@@ -62,9 +62,20 @@ describe('regressions', function() {
     });
   });
 
+  it('issue-2315: cannot read property currentRetry of undefined', function (done) {
+    runJSON('regression/issue-2315.js', [], function(err, res) {
+      assert(!err);
+      assert.equal(res.stats.pending, 0);
+      assert.equal(res.stats.passes, 0);
+      assert.equal(res.stats.failures, 1);
+      assert.equal(res.code, 1);
+      done();
+    });
+  });
+
   it('issue-2406: should run nested describe.only suites', function(done) {
     this.timeout(2000);
-    runJSON('regression/issue-2406.js', [], function(err, res) {
+    runJSON('regression/issue-2406.fixture.js', [], function(err, res) {
       assert(!err);
       assert.equal(res.stats.pending, 0);
       assert.equal(res.stats.passes, 2);
@@ -75,7 +86,7 @@ describe('regressions', function() {
   });
 
   it('issue-2417: should not recurse infinitely with .only suites nested within each other', function() {
-    runJSON('regression/issue-2417.js', [], function(err, res) {
+    runJSON('regression/issue-2417.fixture.js', [], function(err, res) {
       assert(!err);
       assert.equal(res.stats.pending, 0);
       assert.equal(res.stats.passes, 1);
diff --git a/test/integration/reporters.js b/test/integration/reporters.spec.js
similarity index 91%
rename from test/integration/reporters.js
rename to test/integration/reporters.spec.js
index c2f022fe29..9595611829 100644
--- a/test/integration/reporters.js
+++ b/test/integration/reporters.spec.js
@@ -10,7 +10,7 @@ describe('reporters', function() {
     var res;
 
     before(function(done) {
-      run('passing.js', ['--reporter', 'markdown'], function(err, result) {
+      run('passing.fixture.js', ['--reporter', 'markdown'], function(err, result) {
         res = result;
         done(err);
       });
@@ -44,7 +44,7 @@ describe('reporters', function() {
         '</testsuite>'
       ];
 
-      run('passing.js', args, function(err, result) {
+      run('passing.fixture.js', args, function(err, result) {
         if (err) return done(err);
 
         var xml = fs.readFileSync(tmpFile, 'utf8');
diff --git a/test/integration/retries.js b/test/integration/retries.spec.js
similarity index 88%
rename from test/integration/retries.js
rename to test/integration/retries.spec.js
index 56516b3a92..ce76545b00 100644
--- a/test/integration/retries.js
+++ b/test/integration/retries.spec.js
@@ -5,7 +5,7 @@ var bang = require('../../lib/reporters/base').symbols.bang;
 
 describe('retries', function() {
   it('are ran in correct order', function(done) {
-    helpers.runMocha('retries/hooks.js', args, function(err, res) {
+    helpers.runMocha('retries/hooks.fixture.js', args, function(err, res) {
       var lines, expected;
 
       assert(!err);
@@ -46,7 +46,7 @@ describe('retries', function() {
   });
 
   it('should exit early if test passes', function (done) {
-    helpers.runMochaJSON('retries/early-pass.js', args, function(err, res) {
+    helpers.runMochaJSON('retries/early-pass.fixture.js', args, function(err, res) {
       assert(!err);
       assert.equal(res.stats.passes, 1);
       assert.equal(res.stats.failures, 0);
@@ -58,7 +58,7 @@ describe('retries', function() {
   });
 
   it('should let test override', function (done) {
-    helpers.runMochaJSON('retries/nested.js', args, function(err, res) {
+    helpers.runMochaJSON('retries/nested.fixture.js', args, function(err, res) {
       assert(!err);
       assert.equal(res.stats.passes, 0);
       assert.equal(res.stats.failures, 1);
@@ -70,7 +70,7 @@ describe('retries', function() {
   });
 
   it('should not hang w/ async test', function (done) {
-    helpers.runMocha('retries/async.js', args, function(err, res) {
+    helpers.runMocha('retries/async.fixture.js', args, function(err, res) {
       var lines, expected;
 
       assert(!err);
diff --git a/test/integration/suite.spec.js b/test/integration/suite.spec.js
new file mode 100644
index 0000000000..00066a34f4
--- /dev/null
+++ b/test/integration/suite.spec.js
@@ -0,0 +1,42 @@
+var assert = require('assert');
+var run = require('./helpers').runMocha;
+var args = [];
+
+describe('suite w/no callback', function() {
+  this.timeout(1000);
+  it('should throw a helpful error message when a callback for suite is not supplied', function(done) {
+    run('suite/suite-no-callback.fixture.js', args, function(err, res) {
+      assert(!err);
+      var result = res.output.match(/no callback was supplied/) || [];
+      assert.equal(result.length, 1);
+      done();
+    });
+  });
+});
+
+describe('skipped suite w/no callback', function() {
+  this.timeout(1000);
+  it('should not throw an error when a callback for skipped suite is not supplied', function(done) {
+    run('suite/suite-skipped-no-callback.fixture.js', args, function(err, res) {
+      assert(!err);
+      pattern = new RegExp("Error", 'g');
+      var result = res.output.match(pattern) || [];
+      assert.equal(result.length, 0);
+      done();
+    });
+  });
+});
+
+
+describe('skipped suite w/ callback', function() {
+  this.timeout(1000);
+  it('should not throw an error when a callback for skipped suite is supplied', function(done) {
+    run('suite/suite-skipped-callback.fixture.js', args, function(err, res) {
+      assert(!err);
+      pattern = new RegExp("Error", 'g');
+      var result = res.output.match(pattern) || [];
+      assert.equal(result.length, 0);
+      done();
+    });
+  });
+});
diff --git a/test/integration/timeout.js b/test/integration/timeout.spec.js
similarity index 87%
rename from test/integration/timeout.js
rename to test/integration/timeout.spec.js
index b2dfb201f3..33b8e33093 100644
--- a/test/integration/timeout.js
+++ b/test/integration/timeout.spec.js
@@ -4,7 +4,7 @@ var args   = [];
 
 describe('this.timeout()', function() {
   it('is respected by sync and async suites', function(done) {
-    run('timeout.js', args, function(err, res) {
+    run('timeout.fixture.js', args, function(err, res) {
       assert(!err);
       assert.equal(res.stats.pending, 0);
       assert.equal(res.stats.passes, 0);
diff --git a/test/integration/uncaught.js b/test/integration/uncaught.spec.js
similarity index 89%
rename from test/integration/uncaught.js
rename to test/integration/uncaught.spec.js
index 92a0ce5d35..87dde90902 100644
--- a/test/integration/uncaught.js
+++ b/test/integration/uncaught.spec.js
@@ -4,7 +4,7 @@ var args   = [];
 
 describe('uncaught exceptions', function() {
   it('handles uncaught exceptions from hooks', function(done) {
-    run('uncaught.hook.js', args, function(err, res) {
+    run('uncaught-hook.fixture.js', args, function(err, res) {
       assert(!err);
       assert.equal(res.stats.pending, 0);
       assert.equal(res.stats.passes, 0);
@@ -18,7 +18,7 @@ describe('uncaught exceptions', function() {
   });
 
   it('handles uncaught exceptions from async specs', function(done) {
-    run('uncaught.js', args, function(err, res) {
+    run('uncaught.fixture.js', args, function(err, res) {
       assert(!err);
       assert.equal(res.stats.pending, 0);
       assert.equal(res.stats.passes, 0);
diff --git a/test/jsapi/index.js b/test/jsapi/index.js
index 2dbbcb0469..a096186b96 100644
--- a/test/jsapi/index.js
+++ b/test/jsapi/index.js
@@ -11,16 +11,16 @@ var mocha = new Mocha({
 // mocha.reporter('spec');
 require('should');
 
-mocha.addFile('test/suite.js');
-mocha.addFile('test/runner.js');
-mocha.addFile('test/runnable.js');
-mocha.addFile('test/hook.sync.js');
-mocha.addFile('test/hook.sync.nested.js');
-mocha.addFile('test/hook.async.js');
-mocha.addFile('test/acceptance/duration.js');
-mocha.addFile('test/acceptance/fs.js');
-mocha.addFile('test/acceptance/globals.js');
-mocha.addFile('test/acceptance/timeout.js');
+mocha.addFile('test/suite.spec.js');
+mocha.addFile('test/runner.spec.js');
+mocha.addFile('test/runnable.spec.js');
+mocha.addFile('test/hook-sync.spec.js');
+mocha.addFile('test/hook-sync-nested.spec.js');
+mocha.addFile('test/hook-async.spec.js');
+mocha.addFile('test/acceptance/duration.spec.js');
+mocha.addFile('test/acceptance/fs.spec.js');
+mocha.addFile('test/acceptance/globals.spec.js');
+mocha.addFile('test/acceptance/timeout.spec.js');
 
 mocha.run(function(){
   console.log('done');
diff --git a/test/mocha.js b/test/mocha.spec.js
similarity index 100%
rename from test/mocha.js
rename to test/mocha.spec.js
diff --git a/test/ms.js b/test/ms.spec.js
similarity index 100%
rename from test/ms.js
rename to test/ms.spec.js
diff --git a/test/reporters/base.js b/test/reporters/base.spec.js
similarity index 100%
rename from test/reporters/base.js
rename to test/reporters/base.spec.js
diff --git a/test/reporters/json.js b/test/reporters/json.spec.js
similarity index 100%
rename from test/reporters/json.js
rename to test/reporters/json.spec.js
diff --git a/test/reporters/nyan.js b/test/reporters/nyan.spec.js
similarity index 100%
rename from test/reporters/nyan.js
rename to test/reporters/nyan.spec.js
diff --git a/test/runnable.js b/test/runnable.spec.js
similarity index 100%
rename from test/runnable.js
rename to test/runnable.spec.js
diff --git a/test/runner.js b/test/runner.spec.js
similarity index 54%
rename from test/runner.js
rename to test/runner.spec.js
index 37aeb22d6f..ffe4d70e8c 100644
--- a/test/runner.js
+++ b/test/runner.spec.js
@@ -1,55 +1,59 @@
-var mocha = require('../')
-  , Suite = mocha.Suite
-  , Runner = mocha.Runner
-  , Test = mocha.Test;
+var mocha = require('../');
+var Suite = mocha.Suite;
+var Runner = mocha.Runner;
+var Test = mocha.Test;
+var Hook = mocha.Hook;
 
-describe('Runner', function(){
-  var suite, runner;
+function noop() {}
 
-  beforeEach(function(){
+describe('Runner', function() {
+  var suite;
+  var runner;
+
+  beforeEach(function() {
     suite = new Suite('Suite', 'root');
     runner = new Runner(suite);
-  })
+  });
 
-  describe('.grep()', function(){
-    it('should update the runner.total with number of matched tests', function(){
-      suite.addTest(new Test('im a test about lions'));
-      suite.addTest(new Test('im another test about lions'));
-      suite.addTest(new Test('im a test about bears'));
+  describe('.grep()', function() {
+    it('should update the runner.total with number of matched tests', function() {
+      suite.addTest(new Test('im a test about lions', noop));
+      suite.addTest(new Test('im another test about lions', noop));
+      suite.addTest(new Test('im a test about bears', noop));
       var newRunner = new Runner(suite);
       newRunner.grep(/lions/);
       newRunner.total.should.equal(2);
-    })
+    });
 
-    it('should update the runner.total with number of matched tests when inverted', function(){
-      suite.addTest(new Test('im a test about lions'));
-      suite.addTest(new Test('im another test about lions'));
-      suite.addTest(new Test('im a test about bears'));
+    it('should update the runner.total with number of matched tests when inverted', function() {
+      suite.addTest(new Test('im a test about lions', noop));
+      suite.addTest(new Test('im another test about lions', noop));
+      suite.addTest(new Test('im a test about bears', noop));
       var newRunner = new Runner(suite);
       newRunner.grep(/lions/, true);
       newRunner.total.should.equal(1);
-    })
-  })
-
-  describe('.grepTotal()', function(){
-    it('should return the total number of matched tests', function(){
-      suite.addTest(new Test('im a test about lions'));
-      suite.addTest(new Test('im another test about lions'));
-      suite.addTest(new Test('im a test about bears'));
+    });
+  });
+
+  describe('.grepTotal()', function() {
+    it('should return the total number of matched tests', function() {
+      suite.addTest(new Test('im a test about lions', noop));
+      suite.addTest(new Test('im another test about lions', noop));
+      suite.addTest(new Test('im a test about bears', noop));
       runner.grep(/lions/);
       runner.grepTotal(suite).should.equal(2);
-    })
+    });
 
-    it('should return the total number of matched tests when inverted', function(){
-      suite.addTest(new Test('im a test about lions'));
-      suite.addTest(new Test('im another test about lions'));
-      suite.addTest(new Test('im a test about bears'));
+    it('should return the total number of matched tests when inverted', function() {
+      suite.addTest(new Test('im a test about lions', noop));
+      suite.addTest(new Test('im another test about lions', noop));
+      suite.addTest(new Test('im a test about bears', noop));
       runner.grep(/lions/, true);
       runner.grepTotal(suite).should.equal(1);
-    })
-  })
+    });
+  });
 
-  describe('.globalProps()', function(){
+  describe('.globalProps()', function() {
     it('should include common non enumerable globals', function() {
       var props = runner.globalProps();
       props.should.containEql('setTimeout');
@@ -61,19 +65,19 @@ describe('Runner', function(){
     });
   });
 
-  describe('.globals()', function(){
-    it('should default to the known globals', function(){
+  describe('.globals()', function() {
+    it('should default to the known globals', function() {
       runner.globals().length.should.be.above(16);
-    })
+    });
 
-    it('should white-list globals', function(){
+    it('should white-list globals', function() {
       runner.globals(['foo', 'bar']);
       runner.globals().should.containEql('foo');
       runner.globals().should.containEql('bar');
-    })
-  })
+    });
+  });
 
-  describe('.checkGlobals(test)', function(){
+  describe('.checkGlobals(test)', function() {
     it('should allow variables that match a wildcard', function(done) {
       runner.globals(['foo*', 'giz*']);
       global.foo = 'baz';
@@ -81,43 +85,44 @@ describe('Runner', function(){
       runner.checkGlobals();
       delete global.foo;
       delete global.gizmo;
-      done()
-    })
+      done();
+    });
 
-    it('should emit "fail" when a new global is introduced', function(done){
+    it('should emit "fail" when a new global is introduced', function(done) {
+      var test = new Test('im a test', noop);
       runner.checkGlobals();
       global.foo = 'bar';
-      runner.on('fail', function(test, err){
-        test.should.equal('im a test');
+      runner.on('fail', function(_test, err) {
+        _test.should.equal(test);
         err.message.should.equal('global leak detected: foo');
         delete global.foo;
         done();
       });
-      runner.checkGlobals('im a test');
-    })
+      runner.checkGlobals(test);
+    });
 
     it('should emit "fail" when a single new disallowed global is introduced after a single extra global is allowed', function(done) {
       var doneCalled = false;
       runner.globals('good');
       global.bad = 1;
-      runner.on('fail', function(test, err) {
+      runner.on('fail', function() {
         delete global.bad;
         done();
         doneCalled = true;
       });
-      runner.checkGlobals('test');
+      runner.checkGlobals(new Test('yet another test', noop));
       if (!doneCalled) {
-        done(Error("Expected test failure did not occur."));
+        done(Error('Expected test failure did not occur.'));
       }
     });
 
-    it ('should not fail when a new common global is introduced', function(){
+    it('should not fail when a new common global is introduced', function() {
       // verify that the prop isn't enumerable
       delete global.XMLHttpRequest;
       global.propertyIsEnumerable('XMLHttpRequest').should.not.be.ok();
 
       // create a new runner and keep a reference to the test.
-      var test = new Test('im a test about bears');
+      var test = new Test('im a test about bears', noop);
       suite.addTest(test);
       var newRunner = new Runner(suite);
 
@@ -133,22 +138,23 @@ describe('Runner', function(){
       delete global.XMLHttpRequest;
     });
 
-    it('should pluralize the error message when several are introduced', function(done){
+    it('should pluralize the error message when several are introduced', function(done) {
+      var test = new Test('im a test', noop);
       runner.checkGlobals();
       global.foo = 'bar';
       global.bar = 'baz';
-      runner.on('fail', function(test, err){
-        test.should.equal('im a test');
+      runner.on('fail', function(_test, err) {
+        _test.should.equal(test);
         err.message.should.equal('global leaks detected: foo, bar');
         delete global.foo;
         delete global.bar;
         done();
       });
-      runner.checkGlobals('im a test');
-    })
+      runner.checkGlobals(test);
+    });
 
     it('should respect per test whitelisted globals', function() {
-      var test = new Test('im a test about lions');
+      var test = new Test('im a test about lions', noop);
       test.globals(['foo']);
 
       suite.addTest(test);
@@ -161,157 +167,179 @@ describe('Runner', function(){
       test.should.not.have.key('state');
 
       delete global.foo;
-    })
+    });
 
     it('should respect per test whitelisted globals but still detect other leaks', function(done) {
-      var test = new Test('im a test about lions');
+      var test = new Test('im a test about lions', noop);
       test.globals(['foo']);
 
       suite.addTest(test);
 
       global.foo = 'bar';
       global.bar = 'baz';
-      runner.on('fail', function(test, err){
+      runner.on('fail', function(test, err) {
         test.title.should.equal('im a test about lions');
         err.message.should.equal('global leak detected: bar');
         delete global.foo;
         done();
       });
       runner.checkGlobals(test);
-    })
-  })
+    });
+
+    it('should emit "fail" when a global beginning with d is introduced', function(done) {
+      global.derp = 'bar';
+      runner.on('fail', function() {
+        delete global.derp;
+        done();
+      });
+      runner.checkGlobals(new Test('herp', function() {}));
+    });
+  });
 
-  describe('.hook(name, fn)', function(){
-    it('should execute hooks after failed test if suite bail is true', function(done){
-      runner.fail({});
+  describe('.hook(name, fn)', function() {
+    it('should execute hooks after failed test if suite bail is true', function(done) {
+      runner.fail(new Test('failed test', noop));
       suite.bail(true);
-      suite.afterEach(function(){
+      suite.afterEach(function() {
         suite.afterAll(function() {
           done();
-        })
+        });
       });
-      runner.hook('afterEach', function(){});
-      runner.hook('afterAll', function(){});
-    })
-  })
+      runner.hook('afterEach', function() {});
+      runner.hook('afterAll', function() {});
+    });
+  });
 
-  describe('.fail(test, err)', function(){
-    it('should increment .failures', function(){
+  describe('.fail(test, err)', function() {
+    it('should increment .failures', function() {
       runner.failures.should.equal(0);
-      runner.fail({}, {});
+      runner.fail(new Test('one', noop), {});
       runner.failures.should.equal(1);
-      runner.fail({}, {});
+      runner.fail(new Test('two', noop), {});
       runner.failures.should.equal(2);
-    })
+    });
 
-    it('should set test.state to "failed"', function(){
-      var test = {};
+    it('should set test.state to "failed"', function() {
+      var test = new Test('some test', noop);
       runner.fail(test, 'some error');
       test.state.should.equal('failed');
-    })
+    });
 
-    it('should emit "fail"', function(done){
-      var test = {}, err = {};
-      runner.on('fail', function(test, err){
+    it('should emit "fail"', function(done) {
+      var test = new Test('some other test', noop);
+      var err = {};
+      runner.on('fail', function(test, err) {
         test.should.equal(test);
         err.should.equal(err);
         done();
       });
       runner.fail(test, err);
-    })
+    });
 
-    it('should emit a helpful message when failed with a string', function(done){
-      var test = {}, err = 'string';
-      runner.on('fail', function(test, err){
+    it('should emit a helpful message when failed with a string', function(done) {
+      var test = new Test('helpful test', noop);
+      var err = 'string';
+      runner.on('fail', function(test, err) {
         err.message.should.equal('the string "string" was thrown, throw an Error :)');
         done();
       });
       runner.fail(test, err);
-    })
+    });
 
-    it('should emit a the error when failed with an Error instance', function(done){
-      var test = {}, err = new Error('an error message');
-      runner.on('fail', function(test, err){
+    it('should emit a the error when failed with an Error instance', function(done) {
+      var test = new Test('a test', noop);
+      var err = new Error('an error message');
+      runner.on('fail', function(test, err) {
         err.message.should.equal('an error message');
         done();
       });
       runner.fail(test, err);
-    })
+    });
 
-    it('should emit the error when failed with an Error-like object', function(done){
-      var test = {}, err = {message: 'an error message'};
-      runner.on('fail', function(test, err){
+    it('should emit the error when failed with an Error-like object', function(done) {
+      var test = new Test('a test', noop);
+      var err = { message: 'an error message' };
+      runner.on('fail', function(test, err) {
         err.message.should.equal('an error message');
         done();
       });
       runner.fail(test, err);
-    })
+    });
 
-    it('should emit a helpful message when failed with an Object', function(done){
-      var test = {}, err = { x: 1 };
-      runner.on('fail', function(test, err){
+    it('should emit a helpful message when failed with an Object', function(done) {
+      var test = new Test('a test', noop);
+      var err = { x: 1 };
+      runner.on('fail', function(test, err) {
         err.message.should.equal('the object {\n  "x": 1\n} was thrown, throw an Error :)');
         done();
       });
       runner.fail(test, err);
-    })
+    });
 
-    it('should emit a helpful message when failed with an Array', function(done){
-      var test = {}, err = [1,2];
-      runner.on('fail', function(test, err){
+    it('should emit a helpful message when failed with an Array', function(done) {
+      var test = new Test('a test', noop);
+      var err = [
+        1,
+        2
+      ];
+      runner.on('fail', function(test, err) {
         err.message.should.equal('the array [\n  1\n  2\n] was thrown, throw an Error :)');
         done();
       });
       runner.fail(test, err);
-    })
-  })
+    });
+  });
 
-  describe('.failHook(hook, err)', function(){
-    it('should increment .failures', function(){
+  describe('.failHook(hook, err)', function() {
+    it('should increment .failures', function() {
       runner.failures.should.equal(0);
-      runner.failHook({}, {});
+      runner.failHook(new Test('fail hook 1', noop), {});
       runner.failures.should.equal(1);
-      runner.failHook({}, {});
+      runner.failHook(new Test('fail hook 2', noop), {});
       runner.failures.should.equal(2);
-    })
+    });
+
+    it('should augment hook title with current test title', function() {
+      var hook = new Hook('"before each" hook');
+      hook.ctx = { currentTest: new Test('should behave', noop) };
 
-    it('should augment hook title with current test title', function(){
-      var hook = {
-        title: '"before each" hook',
-        ctx: { currentTest: new Test('should behave') }
-      };
       runner.failHook(hook, {});
       hook.title.should.equal('"before each" hook for "should behave"');
 
-      hook.ctx.currentTest = new Test('should obey');
+      hook.ctx.currentTest = new Test('should obey', noop);
       runner.failHook(hook, {});
       hook.title.should.equal('"before each" hook for "should obey"');
-    })
+    });
 
-    it('should emit "fail"', function(done){
-      var hook = {}, err = {};
-      runner.on('fail', function(hook, err){
+    it('should emit "fail"', function(done) {
+      var hook = new Hook();
+      var err = {};
+      runner.on('fail', function(hook, err) {
         hook.should.equal(hook);
         err.should.equal(err);
         done();
       });
       runner.failHook(hook, err);
-    })
+    });
 
-    it('should emit "end" if suite bail is true', function(done){
-      var hook = {}, err = {};
+    it('should emit "end" if suite bail is true', function(done) {
+      var hook = new Hook();
+      var err = {};
       suite.bail(true);
       runner.on('end', done);
       runner.failHook(hook, err);
-    })
+    });
 
-    it('should not emit "end" if suite bail is not true', function(done){
-      var hook = {}, err = {};
+    it('should not emit "end" if suite bail is not true', function(done) {
+      var hook = new Hook();
+      var err = {};
       suite.bail(false);
-      runner.on('end', function() { throw new Error('"end" was emit, but the bail is false'); });
+      runner.on('end', function() {
+        throw new Error('"end" was emit, but the bail is false');
+      });
       runner.failHook(hook, err);
       done();
-    })
+    });
   });
 
   describe('allowUncaught', function() {
@@ -330,27 +358,29 @@ describe('Runner', function(){
   });
 
   describe('stackTrace', function() {
-    var stack = [ 'AssertionError: foo bar'
-      , 'at EventEmitter.<anonymous> (/usr/local/dev/test.js:16:12)'
-      , 'at Context.<anonymous> (/usr/local/dev/test.js:19:5)'
-      , 'Test.Runnable.run (/usr/local/lib/node_modules/mocha/lib/runnable.js:244:7)'
-      , 'Runner.runTest (/usr/local/lib/node_modules/mocha/lib/runner.js:374:10)'
-      , '/usr/local/lib/node_modules/mocha/lib/runner.js:452:12'
-      , 'next (/usr/local/lib/node_modules/mocha/lib/runner.js:299:14)'
-      , '/usr/local/lib/node_modules/mocha/lib/runner.js:309:7'
-      , 'next (/usr/local/lib/node_modules/mocha/lib/runner.js:248:23)'
-      , 'Immediate._onImmediate (/usr/local/lib/node_modules/mocha/lib/runner.js:276:5)'
-      , 'at processImmediate [as _immediateCallback] (timers.js:321:17)'];
+    var stack = [
+      'AssertionError: foo bar',
+      'at EventEmitter.<anonymous> (/usr/local/dev/test.js:16:12)',
+      'at Context.<anonymous> (/usr/local/dev/test.js:19:5)',
+      'Test.Runnable.run (/usr/local/lib/node_modules/mocha/lib/runnable.js:244:7)',
+      'Runner.runTest (/usr/local/lib/node_modules/mocha/lib/runner.js:374:10)',
+      '/usr/local/lib/node_modules/mocha/lib/runner.js:452:12',
+      'next (/usr/local/lib/node_modules/mocha/lib/runner.js:299:14)',
+      '/usr/local/lib/node_modules/mocha/lib/runner.js:309:7',
+      'next (/usr/local/lib/node_modules/mocha/lib/runner.js:248:23)',
+      'Immediate._onImmediate (/usr/local/lib/node_modules/mocha/lib/runner.js:276:5)',
+      'at processImmediate [as _immediateCallback] (timers.js:321:17)'
+    ];
 
     describe('shortStackTrace', function() {
       it('should prettify the stack-trace', function(done) {
-        var hook = {},
-            err = new Error();
+        var hook = new Hook();
+        var err = new Error();
         // Fake stack-trace
         err.stack = stack.join('\n');
 
-        runner.on('fail', function(hook, err){
-          err.stack.should.equal(stack.slice(0,3).join('\n'));
+        runner.on('fail', function(hook, err) {
+          err.stack.should.equal(stack.slice(0, 3).join('\n'));
           done();
         });
         runner.failHook(hook, err);
@@ -359,14 +389,14 @@ describe('Runner', function(){
 
     describe('longStackTrace', function() {
       it('should display the full stack-trace', function(done) {
-        var hook = {},
-            err = new Error();
+        var hook = new Hook();
+        var err = new Error();
         // Fake stack-trace
         err.stack = stack.join('\n');
         // Add --stack-trace option
         runner.fullStackTrace = true;
 
-        runner.on('fail', function(hook, err){
+        runner.on('fail', function(hook, err) {
           err.stack.should.equal(stack.join('\n'));
           done();
         });
diff --git a/test/sanity/sanity.js b/test/sanity/sanity.spec.js
similarity index 100%
rename from test/sanity/sanity.js
rename to test/sanity/sanity.spec.js
diff --git a/test/suite.js b/test/suite.spec.js
similarity index 98%
rename from test/suite.js
rename to test/suite.spec.js
index 7fead0745a..54a1acd667 100644
--- a/test/suite.js
+++ b/test/suite.spec.js
@@ -136,7 +136,7 @@ describe('Suite', function(){
 
         this.suite._beforeAll.should.have.length(1);
         var beforeAllItem = this.suite._beforeAll[0];
-        beforeAllItem.title.should.equal('"before all" hook');
+        beforeAllItem.title.should.match(/^"before all" hook/);
         beforeAllItem.fn.should.equal(fn);
       });
 
@@ -171,7 +171,7 @@ describe('Suite', function(){
 
         this.suite._afterAll.should.have.length(1);
         var afterAllItem = this.suite._afterAll[0];
-        afterAllItem.title.should.equal('"after all" hook');
+        afterAllItem.title.should.match(/^"after all" hook/);
         afterAllItem.fn.should.equal(fn);
       });
       it('appends title to hook', function(){
@@ -205,7 +205,7 @@ describe('Suite', function(){
 
         this.suite._beforeEach.should.have.length(1);
         var beforeEachItem = this.suite._beforeEach[0];
-        beforeEachItem.title.should.equal('"before each" hook');
+        beforeEachItem.title.should.match(/^"before each" hook/);
         beforeEachItem.fn.should.equal(fn);
       });
 
@@ -240,7 +240,7 @@ describe('Suite', function(){
 
         this.suite._afterEach.should.have.length(1);
         var afterEachItem = this.suite._afterEach[0];
-        afterEachItem.title.should.equal('"after each" hook');
+        afterEachItem.title.should.match(/^"after each" hook/);
         afterEachItem.fn.should.equal(fn);
       });
 
diff --git a/test/test.js b/test/test.spec.js
similarity index 100%
rename from test/test.js
rename to test/test.spec.js
diff --git a/test/utils.js b/test/utils.spec.js
similarity index 100%
rename from test/utils.js
rename to test/utils.spec.js